Effective written communication Essay Example | Topics and Well Written Essays - 500 words

Effective written communication - Essay Example Cultural beliefs and perceptions determine the way in which an audience interprets information. Therefore, understanding the audience cultural background makes it possible for a public speaker to craft the message within the audience’s cultural context. Understanding oneself marks the beginning of an effective rapport between a communicator and audience. For instance, a public speaker can only joke to the extent in which he or she is funny. Listening to the audience enables the speaker to know when to pause, repeat, or simply â€Å"allow a light moment to be expressed† (Ellis 124). Self-awareness ensures that the speaker remains in control of the audience at all times. For instance, an audience may laugh at a pronunciation error. However, the public speaker may take quick control and pass it on as a bluff. On the same note, self-awareness enables a public speaker to remain honest to the audience especially when questions are asked. By assessing personal knowledge on the subject matter, a public speaker may decide to or not to answer questions after a presentation. Providing false information may actually raise more difficult questions than anticipated. Public speaking may involve speaking to an audience with unique characteristics. For instance, a public speaker addressing an investment group needs to understand the investment context of the audience. Validating the audience’s beliefs or system of thinking strengthens the bond with the audience. For instance, the speaker might keep echoing ‘return on investment’ because that is what investors believe in. This way the audience will feel the speaker validated their heartfelt sentiments. Another important reason for audience validation is that it puts the speaker as knowledgeable in the subject matter irrespective of whether the speaker has a strong background on the subject or not. Prowess in public speaking and leadership is a continuous process of constant growth and development. One

PRELIMINARY BIBLIOGRAPHY AND OUTLINE Essay Example | Topics and Well Written Essays - 500 words

PRELIMINARY BIBLIOGRAPHY AND OUTLINE - Essay Example Granting of permission to the individuals to live with the individual of his/her choice without any discrimination of gender, age, race, ethnicity and socioeconomic status etc projected immorality and debauchery in society. Only few thinkers belonging to the Devlin’s school of thought advocated the imposition and observing of moral laws; while a large majority of so-called enlightened theorists supported the idea of freedom to a horrible scale. The entire social establishment, because of the very possibility of the unwed mothers’ involvement in prostitution and other deviant behaviors on the one hand, and their children’s possible becoming the victim of torture, assaults, sexual abuse and starvation etc. The young girls also become victim of the abuse at the hands of stepfathers, uncles, teachers, neighbors and strangers. It is therefore, the law enforcing agencies must announce strict punishments and penalties on the individuals responsible for deflowering the girls. The moral values should also be introduced in the light of the sacred teachings manifestly elucidated in the Holy Scripture. Since the Scriptures belonging to all religions lay stress upon morality and ethical values, introducing of moral laws would be imperatively beneficial for the entire society. Berger, P., & Kellner, H. Marriage and the Construction of Reality: An Exercise in the Micro-sociology of Knowledge. In G. Handel, & G. G. Whitchurch (Eds), the Psychosocial Interior of the Family (4th ed., pp. 19-36). New York: Aldine De Gruyter. Web Web 26 May 2012 Cardock, C. & Gardner, J.R. Psychological intervention for parishes following accusations of child sexual abuse In S.J. Rossetti (Ed.). Slayer of the soul: Child sexual abuse and the Catholic Church Mystic, CT: Twenty-Third Publications. 1990 Print Costello, E. Jane, Keeler, Gordon P., and Angold, Adrian Poverty, Race/Ethnicity, and Psychiatric Disorder: A Study of Rural Children American Journal of

Effect of Synthesis Temperature on Nickel-Cobalt Hydroxides

Effect of Synthesis Temperature on Nickel-Cobalt Hydroxides Effect of synthesis temperature on the morphology and pseudocapacitive behavior of Nickel-Cobalt layered double hydroxides Li-Ming Lua, Shan-Shan Xua, Rui-Qi Fenga, Zhan-Bing He b, Tie-Zhen Rena* and Teresa J. Bandoszc a School of Chemical Engineering, Hebei University of Technology, Tianjin 300130 China b State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China c Department of Chemistry and Biochemistryà ¯Ã‚ ¼Ã…’The City college of New York, 160 Convent Ave., New York, NY 10031. * Corresponding author. Tel. +86 22 60204909. Email:[emailprotected] Abstract   Ãƒâ€šÃ‚   A facile one-step method for preparing nickel/cobalt layered double hydroxides (Ni/Co LDH) in a mixture of NH4Cl/NaOH solutions in the temperature range 45-85 oC is introduced. Ni/Co LDH consists of ultrathin nanosheets of various thicknesses assembled into porous nanostructures/microspheres. The mixed solution provides OH, whose amount depends on the temperature, for reactions with Ni2+/Co2+ leading to the formation of hydroxides. The sample prepared at 70  °C shows the highest capacitance of 1142 F g-1 at a current density of 0.5 A g-1.That capacitance decreases about 15 % to 970 F g-1 at a high current density of 10 A g-1. The temperature effect on the arrangement of microsphere is apparent and Ni/Co LDH prepared at 70 oC has the most defectless texture (microspheres). The asymmetrical supercapacitor consisting of this sample as an anode and an activated carbon (AC) as a cathode works in a broad potential window from 0 to 1.6 V. The energy density of the Ni/Co of such a system reaches 58.13 Wh kg-1 at the power density of 160 W kg-1 owing to the intersectional nanosheets and unrestricted accessibility of electrolyte to the reaction centers. Even at a high discharge current density of 2 A g-1, the energy density still remains at 45.78 Wh kg-1 with a power density of 1600 W kg-1. Keywords: mild temperature, layered double hydroxides, energy density, asymmetric supercapacitors. 1. Introduction Nowadays, the development of efficient supercapacitors with high energy density is of paramount importance [1, 2]. Generally, supercapacitors can be classified into electrochemical double layer capacitors and pseudocapacitors [3]. In theory, pseudocapacitors exhibit a higher capacitance and energy density than the double layer capacitors. The latter stores electrical charge mainly at the electrode/electrolyte interface. However, the energy stored in supercapacitors is about 10 times smaller than that in batteries. This severely limits their applications where a high power density is required [4]. Therefore, there is a need to develop and to explore the advanced performance electrode materials for their applications in energy storage devices. Layered double hydroxides (LDH), especially Ni/Co LDH compounds, are considered as materials of promising properties when applied in supercapacitors [5-7]. In their structure Co2+ can be oxidized to conductive CoOOH during redox reactions resulting in the improvement in conductivity of electrode materials [5]. For instance, Ni/Co LDHs hollow microspheres obtained in SiO2 templates exhibited the specific capacitance of 2171 F g-1 at the current density of 1 A g-1 [6]. Another examples are ultrathin NiCo-based LDH prepared at 120  °C, which displayed remarkable specific capacitance of 1537 F g-1 at 0.5 A g-1 [5]. It is important to mention that Ni/Co LDH referred as hydrotalcite-like compounds allow the intercalation of negatively charged anions within the interlayer space [7, 8]. This is expected to enhance the capacitive performance. Thus Lee et al. synthesized ÃŽÂ ±-Ni(OH)2 through exchange of intercalated dodecyl sulfate anions by smaller anions (Cl, NO3, OAc and SO42-). They found that larger anions hindered the mobility of OH ions toward the surface of Ni(OH)2 sheets and Cl intercalated Ni(OH)2 exhibited excellent capacitance. Especially, the Cl ions located in the interlayer space were found as increasing its hydration level and thus enhanced the facile exchange and transport of OH ions [9]. Hu et al. reported the effect of intercalated anions on the size of an interlayer spacing, morphologies, and capacitive performance of four different ÃŽÂ ±-cobalt hydroxides. Their results showed the Cl intercalated sample as the one of the marked capacitance. The good performance was linked to its high proton affinity [10]. In this work, we introduce a wet chemical approach to prepare Cl intercalated Ni/Co LDH. The synthesis is done below 85 °C, which is the lower temperature than those reported in other hydrothermal methods [11, 12]. In designing the method, it was expected that OH ions from the solution of NH4Cl/NaOH will reacts with Ni2+/Co2+ to generate Ni/Co LDH. An important aspect is that the amount of the released OH ions should be affected by the temperature. Thus the synthesis temperature is a factor, which we expect to govern the nanosheets assembling process and thus the final morphology of the materials. The effect of that morphology on capacitive behavior is investigated. 2. Experimental 2.1 Preparation of Ni/Co-LDH microspheres All reagents were of analytical grade and were used without further purification. In a typical synthesis process, 3.75 mmol of Co(NO3)2 ·6H2O and 3.75 mol of Ni(NO3)2 6H2O were dissolved in 20 ml of water to form a pink solution (Solution A). 40 mmol of NH4Cl was added in 0.076 mol L-1 NaOH (180 mL) to form a transparent solution (Solution B); Then, the solution A was poured into 180 ml of the solution B with the final pH value of 9, in which the metal hydroxide mixtures were obtained. After stirring for 5 minutes, the solution was sealed in a glass bottle and transferred into an oven kept at a predetermined temperature (40, 55, 70 and 85  °C) for 15h. After cooled at room temperature, the obtained Ni/Co-LDH samples were washed with ethanol and water several times and dried in an oven at 60  °C for 12 h. The samples are referred to as Ni/Co LDH-x (x represents the reaction temperature of either 40, 55, 70 or 85  °C). 2.2 Characterization methods X-ray diffraction (XRD) patterns were measured on a Bruker D8 Advance diffractometer operated at 40 kV and 40 mA, Cu KÃŽÂ ± radiation source (ÃŽÂ »Ãƒ ¢Ã¢â‚¬ °Ã‹â€  0.154 nm) was used. Fourier transform infrared spectroscopy (FT-IR) experiments were carried out on Bruker Vector 22 infrared spectroscopy in the range of 400 to 4000 cm-1with KBr tablets. Scanning electron microscopy studies (SEM) were performed on JSM-6490LV field emission scanning electron microscope. The sample was dispersed on the conductive tape fixed on the aluminum support. Transmission electron microscope (TEM) analysis was performed on a FEI Tecnai G20 microscope at 200 keV. The elemental analysis of as-prepared powder carried out using X-ray fluorescence spectrometer (XRF, CIT-3000SL). 2.3 Electrochemical tests To evaluate the electrochemical performance of the synthesized materials, thee Ni/Co LDH samples were mixed with acetylene black and polytetrafluoroethylene (PTFE) in a mass ratio of 75:20:5. Homogeneous pastes obtained in ethanol were coated on a nickel foam substrate. The coated nickel foam was then pressed at 10 MPa and the obtained plate was used as a working electrode after dried at 60  °C for 12 h. The cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance (EIS) of the as-obtained samples were carried out on a IM6 ZENNIUM electrochemical workstation in a three-electrode cell. The mass of working electrode was about 8 mg. The capacitance was measured in 6M KOH electrolyte using a platinum wire as a counter electrode and Ag/AgCl as a reference electrode. EIS tests were conducted in a frequency range from 100 kHz to 10 mHz with alternating current oscillation of 5 mV. The electrochemical performance of an asymmetric supercapacitor was invest igated in a two-electrode cell of coin-type (CR2025), in which the prepared materials were used as a positive electrode and activated carbon- as a negative electrode. The experiments were carried out on the Land-CT2001A battery system in the potential range from 0 to 1.6 V. 3. Results and Discussion 3.1. Characterization of materials The typical powder X-ray diffraction (XRD) patterns provide the information on the degree of crystallinity and the crystal structure of the Ni/Co LDH materials (Figure 1a) The distinct characteristic diffraction peaks on XRD patterns at 2ÃŽÂ ¸ 11.1, 22.2, 33.4 and 38.5 are indexed as (003), (006), (009) and (015) plane reflections of the hydrotalcite-like LDH phase, respectively [11, 13]. Increasing the reaction temperature leads to a slight increase in the intensity of the diffraction peaks. According to the Bragg equation, the calculated interlayer space of Ni/Co LDH is 0.79 nm. Ma et al. reported that the layered transitional metal hydroxides nanocones displayed a variety of interlayer space sizes depending on the kind of intercalated ions [12]. The values were 0.8 nm for NO3, 0.92 nm for ClO4, and 0.79 nm for Cl. Our results suggest that Cl ions are present in the interlayer space of the synthesized ÃŽÂ ±-phase compounds. FT-IR spectra of all samples are presented in Figure 1b. The broad band at about 3449 cm-1 is characteristic of the stretching vibration of hydroxyl groups hydrogen-bond to H2O [1]. The band at about 1630 cm-1 represents the bending mode of water molecules [10]. For all samples, three bands at 1476, 1349 and 854 cm-1 are linked to the typical features of carbonate ions [14]. Their presence is linked to the reactivity of hydroxides with atmospheric CO2. Bands below 800 cm-1represent stretching modes of metal-oxygen in the hydrotalcite-like lattice [1]. The band at about 649 cm-1 is assigned to Ni-OH bending. The absorption band at around 514 cm-1 represents the Co-O stretching vibrations [15]. The results indicate that the synthesized materials are nickel and cobalt layered double hydroxides. Scanning electron microscopy (SEM) was used to analyze the morphologies of the obtained Ni/Co LDH materials prepared at different temperatures. Figure 2a shows a typical SEM image of Ni/Co LDH-40. There microspheres with a size around 3 ÃŽÂ ¼m and a small amount of aggregated nanosheets is visible (Fig. 2a inset). The micro-spherical particles consist of numerous interconnected nanosheets with thickness of about 30 nm. The morphology of Ni/Co LDH-55 presented in Figure 2b resembles that of Ni/Co LDH-40. The nanosheets with thickness around 20 nm are gathered in 3-D arrangements (Fig. 2b inset). When the reaction temperature increases to 70  °C, the microspheres of sample Ni/Co LDH-70 become well defined,defectless and uniform (Fig. 2c). Their size distribution is narrow with maximum at 3 ÃŽÂ ¼m. The detailed features of Ni/Co LDH-70 are shown in the Figure 2c (inset) where high-quality 3D flower-like microspheres are visible. The thickness of the nanosheets is about 15 nm. Wh en the Ni/Co LDH material was prepared at 85  °C, the microspheres are not well-defined and some debris are visible (Fig. 2d). The spherical particles have a loose structure and some collapsed nanosheets overlay each other to construct larger sheets. Enlargement of the flower-like microsphere indicates that the nanosheets are interconnected and well-organized in three dimension (Fig. 2d inset). The thickness of nanosheets increases slightly when the temperature increases from 70  °C to 85  °C.    In order to confirm the defectless microsphere/nanosheet morphology of Ni/Co LDH-70 sample, its internal structure has been further investigated by TEM. Figure 3a shows that the microsphere is assembled from nanosheets and the diameter of the microsphere is around 3 ÃŽÂ ¼m. The internal structure of microsphere is spacious and the nanosheets are the aggregates of even thinner layers. X-ray fluorescence (XRF) spectra were recorded for all samples. On the spectra, three marked peaks at 6.93, 7.48 and 8.26 KeV are identified as Co KÃŽÂ ±, Ni KÃŽÂ ± and Ni KÃŽÂ ², respectively. This supports the co-existence of Ni and Co elements in all samples. Moreover, a peak at about 2.62 KeV is assigned as Cl KÃŽÂ ±, which originates from the interlayer anion Cl. It is interesting that the Ni/Co ratio of the as-obtained samples increased gradually with an increase in the temperature. This may be linked to the differences to the solubility constants of hydroxides (Ksp(Co(OH)2 )>Ksp(Ni(OH)2)) and to the effect of temperature on that solubility [11].    The results obtained suggest that the reaction temperature plays a crucial role in the formation of microspheres. The nucleation of Co(OH)2/Ni(OH)2 took places upon the addition of metal ions to the NH4Cl/NaOH solution. In such a system the involvement of OH in the formation of metal hydroxides competes with the formation of ammonia (NH4Cl+ NaOH à ¢Ã¢â‚¬  Ã¢â‚¬â„¢NH4+ + OH + NaCl à ¢Ã¢â‚¬  Ã¢â‚¬â„¢NH3 + H2O, Co2+ + OH à ¢Ã¢â‚¬  Ã¢â‚¬â„¢Co(OH)2, Ni2++ OH à ¢Ã¢â‚¬  Ã¢â‚¬â„¢Ni(OH)2). This affects the amount of OH reacting with metal ions. The size of nanosheets/hydroxide units increases with an increasing temperature owing to more energy provided to the system. This leads to a gradual increase in the sizes of microspheres built of these nanosheets. Even though the temperature range of the alkaline solution was not very broad and between 40 and 85  °C, 70  °C was found as the only temperature resulting in the uniform and defectless microspheres. Lower temperature of the system has an adverse effect on the formation of microspheres, likely due to the thicker nanosheets than those formed at 70 oC. On the other hand, higher temperature likely leads to collapsing of the formed microspheres [16]. 3.2 Electrochemical tests To evaluate the electrochemical performance of the synthesized materials, the cycling voltammetry (CV) curves were measured for Ni/Co LDH materials at a scan rate of 5 mv s-1 in 6M KOH aqueous solution (Fig. 4a). It is clearly seen that all curves exhibit a pair of redox peaks. An anodic peak is around 0.45 V and a cathodic peak- at about 0.2 V. They represent typical features of Faradaic pseudocapacitance representing the following reactions [6, 17]. Ni(OH)2 + OH à ¢Ã¢â‚¬  Ã¢â‚¬  NiOOH +H2O +e-  Ãƒâ€šÃ‚  Ãƒâ€šÃ‚  Ãƒâ€šÃ‚  Ãƒâ€šÃ‚   (1) Co(OH)2 + OH à ¢Ã¢â‚¬  Ã¢â‚¬  CoOOH+H2O+e-  Ãƒâ€šÃ‚  Ãƒâ€šÃ‚  Ãƒâ€šÃ‚  Ãƒâ€šÃ‚  Ãƒâ€šÃ‚   (2) CoOOH+OH à ¢Ã¢â‚¬  Ã¢â‚¬  CoO2+H2O+e-  Ãƒâ€šÃ‚  Ãƒâ€šÃ‚  Ãƒâ€šÃ‚  Ãƒâ€šÃ‚  Ãƒâ€šÃ‚  Ãƒâ€šÃ‚  Ãƒâ€šÃ‚  Ãƒâ€šÃ‚  Ãƒâ€šÃ‚  Ãƒâ€šÃ‚   (3) The shapes of the CV curves indicate that Ni/Co LDH-70 has the highest specific capacitance [18]. To further investigate the capacitive behavior of our electroactive materials, the galvanostatic charge-discharge (GCD) measurements were performed in a three-electrode system and the specific capacitance (Cs) was calculated from the following equation (4): (4) Where I is a constant discharge current (A), Άt is discharge time (s), ΆV is the potential difference, m is the mass of active material. The GCD measurements in a potential window of 0-0.5 V are recorded at a current density of 1 A g-1 (Fig. 4b). The results show that the discharge time of Ni/Co LDH-70 is much longer than those of other electrodes. Based on the GCD curves, the specific capacitance was calculated. The values are 777, 608, 114,2 and 1017 F g-1 for Ni/Co LDH-40, Ni/Co LDH-55, Ni/Co LDH-70, and Ni/Co LDH-85, respectively. Wang et al. [19] prepared Ni/Co nanoplates using a surfactant assisted method. The rough nanoplates of an increased surface area displayed the specific capacitance of 311 F g-1, which was 2.3 times higher than that of smooth-surfaced Ni/Co nanoplates. It was concluded that creating more interspaces or a larger area can improve an electrochemical performance [19, 20]. Amongst our samples, Ni/Co LDH-70 with three dimensional defectless microspheres exhibits the highest capacitance. This texture promotes the electrolyte access to the more active centers than those available to electrolyte i n more defected microspheres of the samples synthesized at other temperatures. Since Ni/Co LDH-70 exhibits the best performance, its CV curves were measured at the scan rates 5, 10, 20, 50 and 100 mV s-1 (Figure 4c). The shape of the CV curves remains almost unchanged with an increase in the scan rate, suggesting a quick CV response with fast potential sweep and promising capability for energy storage [21]. In addition, all CV curves present a well-defined reduction and oxidation peaks with a slight shift in both cathodic and anodic peak potentials with an increasing scan rate. This suggests that an ion diffusion rate limits the redox reaction [22]. GCD curves of Ni/Co LDH-70 at different current densities (Fig.4d) show two visible voltage plateaus in the charge and discharge parts of the plots. More importantly, the GCD curves of Ni/Co LDH-70 are highly symmetrical at various current densities, indicating fast and good electrochemical reversibility of the Faradaic redox reactions. The capacitance of Ni/Co LDH-70 calculated from the GCD curves at the current densities of 0.5, 1, 2, 3, 5, 8 and 10 A g-1are 1142, 1130, 1098, 1081, 1053, 994, and 970 F g-1, respectively. The capacitance values gradually decrease with increasing current densities from 0.5 to 10 A g-1, owing to the fast electron transfer [23]. Ni/Co LDH-40, Ni/Co LDH-55 and Ni/Co LDH-85 exhibit the capacitance of 777, 608 and 1017 F g-1, respectively. It is important to mention that the specific capacitance of Ni/Co LDH-70 is 970 F g-1 at a high current density of 10 A g-1, and it consists of 84.9% of that at 0.5 A g-1. For Ni/Co LDH-40, Ni/Co LDH-55 and Ni/Co LDH-85 , the corresponding values are at 610, 392 and 812 F g-1 representing the capacitance retentions of 78.5%, 64.5% and 79.8%, respectively. Such differences in the electrochemical performance can be explained by the morphology differences between the samples. As discussed above, the Ni/Co LDH-70 sample consists of uniform three dimensional microspheres built of nanosheets with the interspaces between them. These spaces increase the electrolyte access to the surface of the active materials. Thus the interconnected thin nonosheets in defectless microspheres provide more active sites for reactions with the electrons, which leads to the high capacitance [24, 25]. Electrochemical impedance spectroscopy (EIS) measurement is one of the fundamental methods to examine the electrochemical behavior of electrode materials. The Nyquist plots for the Ni/Co LDH materials in a frequency range of 100 kHz to10 mHz are displayed in Figure 5a. All the impedance spectra of the Ni-Co LDH materials are very similar to each other with a small semicircle at high-frequency and an inclined line at low-frequency [26]. The point intersecting with the real axis (Z) at the high frequency represents the internal resistance, which includes the total resistances of intrinsic resistance of active materials, electrolyte resistance. and the contact resistance at electrolyte/electrode interface (Fig. 5a inset) [27]. This value is almost the same for all electrodes. The semicircle at the high frequency corresponds to the charge transfer resistance (Rct) [28]. At low frequencies, the liner part shows the Warburg impedance resulting from the ion diffusion resistance of the elect rolyte in the active material [21]. Ni/Co LDH-70 exhibits the smallest semicircle diameter, which suggests the minimum charge transfer resistance and maximal electrochemical conductivity. The straight line at low frequencies range is close to Z axis. This suggests that the capacitive performance is not only related to the diffusion process but double layer can also form [21, 29]. The effective ions diffusion and electron transfer of the Ni/Co LDH-70 electrode can be linked to the well-organized three dimensional and defectless micropheres [30]. For the evaluation of the feasibility of practical application of our materials, we constructed the asymmetric supercapacitors with Ni/Co LDH-70 as a positive electrode and activated carbon (AC) as a negative electrode in 6 M KOH solution. The charge-discharge measurements of the Ni/Co LDH-70 were carried out at the current density range from 0.2 to 2 A g-1 with an operating potential from 0 to 1.6 V (Fig. 5b). All curves show the symmetric-like shape, indicating the high electrochemical reversibility of the process. In addition, Ni/Co LDH-70 displays a small voltage drop at the beginning of the discharge process due to the internal resistance [31]. The values of specific capacitance of Ni/Co LDH-70 calculated from the galvanostatic charge -discharge curves are 163.5, 151, 137, 133 and 129 F g-1 at current densities of 0.2, 0.5, 1, 1.5 and 2 A g-1, respectively. And 78.7% of the capacitance is retained when the current density increases from 0.2 to 2 A g-1. For comparison, the specif ic capacitances of all supercapacitors tested are collected in Table 2. The supercapacitors of Ni/Co LDH-40, Ni/Co LDH-55 and Ni/Co LDH-85 show the specific capacitance of only 109, 86 and 150 F g-1 at 0.2 A g-1. They still keep 84, 62 and 117 F g-1 at 2 A g-1, respectively. The capacitances of Ni/Co LDH-40, Ni/Co LDH-55 and Ni/Co LDH-85 maintain at 77.2%, 72.3% and 78.2%, respectively, when the current density increases from 0.2 to 2 A g-1. Based on those specific capacitance values, the energy and power densities of supercapacitors were further calculated ( and )[32]. Figure 5c shows that the energy densities decrease gradually with the increase in the power densities for all cells. At the same power density, the energy density of Ni/Co LDH-70 is much higher than those of other cells, which means that the Ni/Co LDH-70 cell has superior performance in terms of both energy and power density. The energy density of the Ni/Co LDH-70 is 58.13 Wh kg-1 at the power density of 160 W kg-1. Even at a high discharge current of 2 A g-1, the energy density still remains at 45.78 Wh kg-1 at a power density of 1600 W kg-1. Compared to other samples, the asymmetric supercapacitor of Ni/Co LDH-70 exhibits a significant improvement in both power density and energy density. This may be due to its broad potential window of 0-1.6 V and the high specific capacitance. The well-defined three dimensional microspheres of Ni/Co LDH-70 lead to the excellent energy-power combination. The results are comparable with those reported in the literature [5, 6]. For instance, Li et al. reported a new synthetic method for preparation of 16 nm-ultrathin NiCo-based layered double hydroxides (LDH) in an ethylene glycol solution. Their assembled asymmetric capacitor exhibited an energy density of 33.7 Wh kg-1 at power density of 551 W kg-1 with a 1.5 V operating voltage [5]. Tang et al. synthesized nickel cobalt double hydroxide nanoflowers with various Ni/Co ratios using a simple hydrothermal process at 120  °C. Their asymmetric supercapcitor exhibited 19.4 Wh kg-1 at 80.5 W kg-1, and even 20.6 Wh kg-1 at 3.93 kW kg-1 [6]. Cycling stability is a prime factor for evaluating the practical performance of asymmetric supercapacitors. Figure 5d collects the capacity for 2000 cycles of charge-discharge measurements between 0 and 1.6 V at a current density of 1 A g-1 in a two-electrode system. The capacitances of all Ni/Co LDH remains almost unchanged. With an increasing cycle number, the interfacial contact between the active material and a nickel foam may deteriorate, owing to the volume change of the active material during charge-discharge process. This might lead to a higher ohmic resistance of the asymmetric supercapacitors [33]. The calculated capacitances from GCD curve retain about 84.7%, 88.4%, 92.2% and 91.5% of their original capacitances after 2000 cycles for Ni/Co LDH-40, Ni/Co LDH-55, Ni/Co LDH-70 and Ni/Co LDH-85, respectively. The asymmetric supercapacitor of the Ni/Co LDH-70 shows a better cycling stability than those reported for other supercapacitors consisting of Ni/Co hydroxides [5, 6]. 4. Conclusions Ni/Co LDH of diverse morphologies determined by different particle sizes and thicknesses of nanosheets have been successfully prepared at various reaction temperatures in NH4Cl/NaOH mixture. Apparently the temperate affects the amount of OH and the kinetic of its release. Both those factors govern the morphology of assemabled Ni/Co LDH. The synthesized materials showed differences in their electrochemical performance. The Ni/Co LDH-70 (prepared at 70 °C) consists of uniform, defectless and well-defined microspheres with diameters around 3 ÃŽÂ ¼m. These 3-D microspheres are constructed from interconnected ultrathin nanosheets. Such an arrangement provides the space accessible to electrolyte and enables an efficient utilization of active centers. It also results in a high stability of the electrode upon cycling. Ni/Co LDH-70 shows the highest capacitance of 1142 F g-1 at a current density of 0.5 A g-1 and the value is still at 970 F g-1 at a high current density of 10A g-1, which is 84.9% of that at 0.5A g-1. The asymmetrical Ni/Co LDH-70 // activated carbon (AC) supercapacitor was tested in two-electrode system with a wide potential window of 0-1.6V. The results show that highest energy density of the Ni/Co LDH-70 reaching 58.13 Wh kg-1 at the power density of 160 W kg-1. Even at a high discharge current of 2 A g-1, the energy density still remains at 45.78 Wh kg-1 at a power density of 1600 W kg-1. Acknowledgement This work was supported by China Scholar Council, the Scientific Research Foundation for the returned overseas Chinese Scholars, State Education Ministry and Hebei Provincial Key Lab of Green Chemical Technology High Efficient Energy Saving, School of Chemical Engineering Technology, Hebei University of Technology and Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University. References [1] T. Yan, Z.J. Li, R.Y. Li, Q. Ning, H. Kong, Y.L. Niu, J.K. Liu, Nickel-cobalt double hydroxides microspheres with hollow interior and hedgehog-like exterior structures for supercapacitors, Journal of Materials Chemistry, 22 (2012) 23587-23592. [2] H.N. Ma, J. He, D.B. Xiong, J.S. Wu, Q.Q. Li, V. Dravid, Y.F. Zhao, Nickel Cobalt Hydroxide @Reduced Graphene Oxide Hybrid Nanolayers for High Performance Asymmetric Supercapacitors with Remarkable Cycling Stability, Acs Applied Materials Interfaces, 8 (2016) 1992-2000. [3] W.P. Sun, X.H. Rui, M. Ulaganathan, S. Madhavi, Q.Y. Yan, Few-layered Ni(OH)(2) nanosheets for high-performance supercapacitors, Journal of Power Sources, 295 (2015) 323-328. [4] T. Yan, H.Y. Zhu, R.Y. Li, Z.J. Li, J.K. Liu, G.L. Wang, Z.Q. Gu, Microwave synthesis of nickel/cobalt double hydroxide ultrathin flowerclusters with three-dimensional structures for high-performance supercapacitors, Electrochimica Acta, 111 (2013) 71-79. [5] R. Li, Z. Hu, X. Shao, P. Cheng, S. Li, W. Yu, W. Lin, D. Yuan, Large Scale Synthesis of NiCo Layered Double Hydroxides for Superior Asymmetric Electrochemical Capacitor, Scitific Report, 6 (2016) 18737. [6] Y. Tang, Y. Liu, S. Yu, W. Guo, S. Mu, H. Wang, Y. Zhao, L. Hou, Y. Fan, F. Gao, Template-free hydrothermal synthesis of nickel cobalt hydroxide nanoflowers with high performance for asymmetric supercapacitor, Electrochimica Acta, 161 (2015) 279-289. [7] B. Mavis, M. Akinc, Three-component layer double hydroxides by urea precipitation: structural stability and electrochemistry, Journal of Power Sources, 134 (2004) 308-317. [8] T. Hibino, H. Ohya, Synthesis of crystalline layered double hydroxides: Precipitation by using urea hydrolysis and subsequent hydrothermal reactions in aqueous solutions, Applied Clay Science 45 (2009) 123-132. [9] J.W. Lee, J.M. Ko, J.-D. Kim, Hierarchical Microspheres Based on alpha-Ni(OH)2 Nanosheets Intercalated with Different Anions: Synthesis, Anion Exchange, and Effect of Intercalated Anions on Electrochemical Capacitance, J Phys Chem C, 115 (2011) 19445-19454. [10] Z.A. Hu, Y.L. Xie, Y.X. Wang, L.J. Xie, G.R. Fu, X.Q. Jin, Z.Y. Zhang, Y.Y. Yang, H.Y. Wu, Synthesis of alpha-Cobalt Hydroxides with Different Intercalated Anions and Effects of Intercalated Anions on Their Morphology, Basal Plane Spacing, and Capacitive Property, J Phys Chem C, 113 (2009) 12502-12508. [11] H. Chen, L. Hu, M. Chen, Y. Yan, L. Wu, Nickel- Cobalt Layered Double Hydroxide Nanosheets for High- performance Supercapacitor Electrode Materials, Advanced Functional Materials, 24 (2014) 934-942. [12] X. Liu, R. Ma, Y. Bando, T. Sasaki, A General Strategy to Layered Transition-Metal Hydroxide Nanocones: Tuning the Composition for High Electrochemical Performance, Advanced Materials, 24 (2012) 2148-2153. [13] J. Huang, T. Lei, X. Wei, X. Liu, T. Liu, D. Cao, J. Yin, G. Wang, Effect of Al-doped beta-Ni(OH)(2) nanosheets on electrochemical behaviors for high performance supercapacitor application, Journal of Power Sources, 232 (2013) 370-375. [14] M. Li, K.Y. Ma, J.P. Cheng, D.H. Lv, X.B. Zhang, Nickel-cobalt hydroxide nanoflakes conformal coating on carbon nanotubes as a supercapacitiv

Why Some Forms of Opposition Were More Successful than Others in the Pe

Why Some Forms of Opposition Were More Successful than Others in the Period 1798-1921 The Act of Union, 1801. Ireland was to be joined to Great Britain into a single kingdom, the Dublin parliament was to be abolished. Ireland was to be represented at Westminster (all were Anglicans), the Anglican Church was to be recognised as the official Church of Ireland, no Catholics were to be allowed to hold public office and there was to be no Catholic Emancipation. Immediately we can see from this that any form of opposition would be to destroy this act. Fundamentally it destroyed all catholic rights and forced them to renounce their Catholic faith and take on a Protestant one. In Ireland Daniel O'Connell developed a reputation for his radical political views. By the early 1920's the Irish people started to listen to O'Connell's views and he gathered a large group of supporters. O'Connell had many aims in his political career. O'Connell's goal was to repeal against the act of union. When the Act of Union was passed in 1801 it did not help the Irish. It simply brought problems and distrust to the Irish people. O'Connell organised a meeting to discuss the repeal of the Act of Union, three quarters of a million Irish turned up. They were known as 'Monster Meetings'. We can see that O'Connell successfully created an Irish nation movement and completely changed the British view of the Irish. The British now had a certain amount of respect for the Irish and even feared and threatened their movement. This support from the people could show us the later success that O'Connell has in his opposition, as a movement without opposition would ultimately ... ...d in the cruellest yet effective way possible. Collins achievements were many: he helped fight the British to a stalemate by changing the rules of warfare and setting up an intelligence network to rival the Empire's. He helped negotiate a treaty, which gave Ireland the first stepping stone to become a Republic, and oversaw Ireland's turbulent transition to democracy. His achievements were, however, not without a price. He precipitated the bloody War of Independence against the British and the treaty deal brought back from London split the country into two fiercely opposing halves and plunged the country into the throes of a traumatic civil war. Thus ultimately opposition needed to be well organised and have enough support to succeed, constitutional nationalism had this through its methods of working through the system.

Chance vs. Fate Essay

Do you ever tried to think, what if chance and fate face a fight? Who do you think would be the winner? And who do you think would be the looser? If one people began to fight his chance and his fate,. Who do you think would make him feel happier? Is it the chance who gave him chance, or is it fate that decide his life. Maybe most of you think that chance would be the obvious winner, for more people is now wanted to take a chance than fate. But how ever what if I told you that fate is stronger than chance? What if I tell you that if you need to choose a choice between chance and fate,. I must tell you that fate is the better choice than chance. That fate can assure you that you’ll never regret for choosing it than chance. For fate must knew the Rightful one than chance. How? Because I had a very interesting story about chance and hope. That made me realized what’s The best choice for me. And this is just happened to me a month ago before December enter the year. Since birth I have a childhood friend that became part of my life. Each and every day we are together. Those days are just passing by and our relationship as friends became more deeper and deeper that I came to the point I fall in love with him secretly. But instead of telling it into him, I decided to not mention my feelings anymore for our friendship has been gone through the years. And I don’t want to ruin that friendship. But fate never gives a consideration, into me. My parents decided to continue my high school at manila, together with my sister. And when my last day in our province came, I let him knew that I was leaving. That time I wanted to tell him the truth. I have the chance but I let it go. I never succeeded telling into him that I really love him. After that event I really hate fate for deciding what for my life. I do really hate it for I was such in a poor condition that time. But two years had passed. No communication for the last two years. And when I spent m y semestrial break in our province after two years, I really did see the things change. When I came back home I saw him. And flashback remains into my head. But instead of smiling into him, I pretend not to see anyone. until he said to me that he was fallen in love with me. But as hearing the soft words he had spoken I cant really imagined that all the old feelings of yesterday is now coming back faster. But of course, I remembered he was my friend. And I like him too. But what the heck? After some month I rejected him even though I loved him. And that he quits on asking. After some month December came a number texted me and ask who it was. But I was shocked It was my classmate since I’m in grade six. If I remembered nothing go right with our relationship as classmate. He was my first crush during my elementary days, I remember how he always make me cry during the time. I remember how he spoke word into me in front of everybody else. I remember it all. We never had the time to speak even a little single word without fighting with each other. Until graduation we never had. And now his here and te lling me if he have the chance. Normally, I won’t forgive him for the past few years for what he has done. I don’t want to forgive him but my heart likes to. And I can’t even understand of all this years, why is the feeling of long old love was coming back again? But then time gives me chance to think of. And I really found out what it has to be. That my classmate is my real one true love for that I have realized that: On our situation of my best friend, we have the very big chance but fate decide. And give me the real answer. And time gave me realization to know what is meant to be. Name: Mariflor B. Villanueva Essay no: 4 Date: December 6 2012 â€Å"My Ambition† I was young when I tell many of my ambition in life. One I must tell, I wanted to be a teacher because, I wanted to wrote on the board and make my student copy what I write. I also told my mom that I wanted to become a scientist someday because I wanted to be famous and known as a knowledgeable person. Some days, I shouted I wanted to become a business woman it because, I wanted to hold money. I wanted to be a house designer because I wanted to create my own house. I wanted to become a fashion designer it because, I want to make some gowns and wedding dress. So many to mention when I was kid. Too many ambition and many reasons why I wanted to be something like that. Imagine. When I was kid I have many dreams and ambition having some many reasons to tell. I am a dreamer girl when I was kid. But now how, I wonder so many things. I questioned all what I have said during my days of childhood. I don’t want to be a teacher because what I heard nowadays is just: â€Å"just take education, you don’t have enough knowledge† what they mean is that teachers nowadays is just not that famous now. I don’t wish to be scientist for I already know, I can’t be a knowledgeable person. I will never take the path of being a business woman because I don’t know math at all. I will never wish to be a house designer for I am no good at sketching a house. And most. I never imagined myself being a fashion designer for that I donâ €™t wanted anymore to take that job for I believe it wasn’t my future. I have nothing now. I have nothing now to say what I wanted to be in the near future. I can’t just imagined myself of a perfect ambition. All my dreams in my childhood days fade away and if I’m a dreamer in my childhood days, now I feel I am now so useless of the community to think what I wanted. I don’t feel like I belong to any course I have think. Now I am just a little girl without a dream for her future. Until I accidentally broke a glass. I saw the glass shinning when it is in the sun. I imagined it as a diamond sparkling. And the idea came to my mind. How about if, I try to make it a jewellery? Like necklace? It is nice to have an own sketched necklace right? So I took the broken glass I search some metals that can be fold, and an old rope of necklace. I took some help with my uncle for chaining the pattern I did. And he well made it very nice. At the end, I was so happy it was my own crafted jewellery. Starting that day, I decided to be a jewellery designer. Not because I am inspired doing some Jewellery, or just I wanted to be famous in e veryone, but now†¦ I suddenly realized how to have a good ambition and reason. My reason that, I wanted to became a jewellery designer someday not because of anything but I do want to become jewellery designer because, I want someday to see people wearing my designs around their neck, their arms, their finger, and such many else. I wanted to become a merely jewellery designer to see how people love my designs. That was my ambition and my reasons for why I liked to become what I am dreaming now. Name: Najeeb A. Imam Essay no: 3 Date: December 6 2012 â€Å"To be the Highest† When I was young, I said to myself that I wanted to be having the highest position. Highest that No one will reach me as I am. And that I thought that to be the highest I must need to be the President of this country. To rule anyone, to make this country more successful more than any Other country. But I was wrong knowing out that to be a president you’re not consider as a high Person. I realized inside myself. So I change what I wanted. And now, I said to be the highest I need to be a successful doctor. Because doctor saves life. Doctor saves many lives of human. Without a doctor everyone will be sick and there will be more people dying. But realizing to be A doctor is not the path in a way to be the highest. But what I had realize this pass few years that To be one of the highest person, you don’t need to be a president, doctor, scientist, engineer or What so ever. Because I realized, to be the highest person, you must have to be a teacher for everyone. In order To be a successful man, I need to be a teacher. Because teacher is the highest position all this Time. Why teacher? Maybe you’re wondering my teacher? Well it because, without a teacher, There will no presidents, no engineer, no scientist, no doctor, and no one. Because to be in one Great position, you would first need to learn something. To have a knowledge in order to be a Successful man. All o the knowledge of the workers now, is well made by a great teacher. A Great teacher that lead them to the right path. A nice teacher that teach everything in to her/his Student. That is why, I decided to be someday, I wanted to be a teacher. Not just an ordinary teacher but I wanted to be the teacher of everyone. Who will teach, and lead everyone in the right path. I I wanted to be a teacher it because for me teacher is the best. For me no one would ever compare The value of a teacher to the value of other. For teacher, knows the best, teacher lead the way, a teacher who’s gonna lead her/his student in The right path. A teacher that everybody loves. And if someday I will be a successful teacher I promised that I will teach the value of a teacher. Name: Najeeb A. Imam Essay no: 4 Date: December 6 2012 â€Å"To write† If you wanted to write a something, a poem, a paragraph, or an essay, how did you write freely? Do you usually, express you’re feeling at what you are writing? Or do you just write too Generally? If you will ask me how I write or how I wrote just like this, I would tell you that just write what You feel, and write like youâ⠂¬â„¢re just sharing. Don’t be so afraid if you will commit a mistake Don’t be shy for its everybody face mistake. If you wanted to write nicely that you want to show The world what have written don’t be so afraid. Because it is not in grammar, or penmanship, Can test how really good you are in writing or expressing idea. It is not tested by how you wrote Long, or how many incredible word do you know, but definitely it is not tested on how you’ve Written a thousand words. To test that you are good in writing, is not based on how you wrote your essay, your poem, your Paragraph. But the real question here is that†¦ How many people have been interested to read what you have written? How many of them Appreciate it? How many of them did tell you you’re writing is amazing. The question is how Many readers did you gain when you shared you’re essay? Are they are few? Or they are just as Many? Because in writing essay, a thousand word is not the point. A beautiful penmanship is not the Requirements here. But it is the one that commonly tested here is by how you’re e ssay your Poem, your paragraph, inspired other? Essay is tested by which you write the importance of your Topic. Essay depend in what is its components and substance. An essay, depends to what larger Meaning you have according to the topic. An essay depends to what it its substance. If it has a good meaning, or it just an essay that have nonsense things. If I am about to ask you, What contains your essay? Are you that willing to say that you’re essay is nice and meaningful? Or you will just crumpled it because you didn’t write at all instead you just earn some thousand Word that has no meaning at all. My dearest reader, of this essay that I wrote, I hope you all get what’s my point in here. I hope That you get what I said and what I had taught you. That a real essay don’t contain million words Or beautiful penmanship, but a real essay is one of the great things, that no matter how short Your essay is†¦ if you have the most meaningful one then don’t be shy. For once again, essay is not to earn a million words but essay is for the a better meaning that Insp ire other to write some. Name: Kins Jonas Go Essay no: Date: December 6 2012 â€Å"Cellphone† As our worlds began to change to be a modern one, many have change. So many things that help Us through our daily living, electricity, transportation, and technology. It is good to think we are Now totally modern. That through the years we all now have the change. And one proof of it is the cell phone we use. Don’t you think the maker of cell phones is clever? Because in some other way, he/she used to invented a very interesting one. A very useful one to Us. Because without this technology maybe we are having hardships through communication. If there were no phones, can you imagine life? Well I think no right? Because our modern world Now is, full of phones. Everywhere you can see it. And maybe half of our population now is Having a phones now. Can you imagine how important phones are? Can you imagine how they are important to people Now? Students! For students like me, it is important because I used to used phones from my Daily living. Because the benefits that it gives me is very helpful to me. Very helpful that you Can call if there is emer gency. You can take communication when you miss your mom or your Dad when they are far away. Using cell phones you don’t worry that much with communication. So it is. Indeed phones are useful but in any other way it was harmful. Why? It because some User of phones use phones in a harmful one. They used phones for blackmails for someone, they Used phones to bully someone, they used phones to harm someone. The phones are not just safe. Because in any other way, it has a harmful effects that affect Everyone. When the phone made the user addicted so much, some possibilities may occur that a students Who use phones will destroy his path in studies. That was a negative effect to a students. Someytimes or somehow I wanted to warn everyone that one thing has a limitation. It couldn’t Be good forever. Like phones. Phones brings harmful and useful effect into us. Name: Kins Jonas Go Essay no: 4 Date: December 6 2012 â€Å"A diary† What is a diary? Did you ever tried to write one? How was the feeling of keeping a diary? Did you use to let everyone read it? Or do yo u just kept it secretly. A diary is something that a holds to the memories you write each and every day. A diary that Holds so many secret beyond loves, llife, and many more. A diary is something that you write Late at night. A diary is something that holds half personality of someone. And I ever tried to read one. I have already read the diary of Anne Marie Frank. A teen ager girl Who is a Jew. Do you know that at the very young age, Anne use to write diary, a diary that Touches the heart of the readers. A diary that inspired other to write one. As I open and read her diary, I thought she only wrote what’s happening into her daily Life. But I was wrong finding it. Because what she had written is that the memories, of Daily events of her life. That somehow, in her life, and at the very young age, she did to kept A very interesting diary. That how I wished someday, I could just write a diary that inspire others. And if I ever Gonna start to write a diary, I would definitely write the memories I can keep forever. That I can keep until I grew old. That someday when I wrote one I swear that I can inspire everyone Who reads it. That may will listed me to the famous journalist who had left a diaries. And in order to be one of them, starting today, I will never be†¦ afraid to have wrong grammar For that I believe that everybody commits mistake like I do. And isn’t it were you commit Mistake there you gain a little correction? That you’ll learn. And I suddenly realized too that To kept a diary burdens sometimes the problems you feel deep inside. That when you don’t have A friend to be trust you just can’t help but to wrote what you have feel deep inside. That how ever you can assure the you’re secret is safe right?

Brinvillier

She clearly writes a second hand account of the B Renville women's' maniac and unfortunate plan with her later repercussions. Prompting the s Tory ,†this was still the only thing talked about in Paris,† this story tells the tale of a woman's purr e desires and her extreme measures of poisoning her husband. Madame De S' view's sets up her blabs opinion towards the account by using her elevated Dalton.Thus showing her tone an d the execution of the plot. Throughout Madame's letter, she Is able to narrate her purpose dramatic her ideas. And use organizational tools to aid her overall sympathy for the e Berliners woman. Although Seven's is depicting an event, she seamlessly connects her supporting data of her opinions towards the Berliner woman. She starts off noting the women's initial t Houghton and plans for her situation. As she depicts her crime, she leaves no room for the reader to interpret his woman as a good citizen.Seventeen's short summary of the account forces the dual once to trust her opinion and agree with her by the end coming to the conclusion that this w Oman receives no redemption. † And, it may be supposed, that we now inhale what remains of her. † Finally, by using her repetitive strategies, she is able to successfully sway the reader towards what she wants them to believe. Helping Madame De Giving's is her elevated diction. This allowing her create an elite opinion as well as persuading her readers.She creates a dramatic tone almost more than the average author to depict the seventy of both her crime and her execution. She leads t he reader suck her with horror†. She is able to utilize a simple summary yet integrate words like shudder inning and horror to emphasize the importance of the story. Madame has the advantage in her I otter to help depict her version of the story yet still remain true to the main idea. Lastly her organizational tools aid her success of both stating her opinion and narrate Eng her story.Sh e starts out with her impacting one sided headline intriguing the audience e to read her letter at a glance. She creates a steady flow of events streamlined with detailed word choice and extreme opinions. Closing out her letter, she solidifies her views. The Berliners whom an to Madame De Giving's is nothing but a murderous wench remaining completely of ids approval through the entirety of the essay. She is very clever in her organizational set up to Cree ate an easily attainable one sided agreement.And lastly, her clever closing remarks, â€Å"It is to e hoped that we shall not inhale her murderous instincts also,† complete her overall purpose of the letter. Overall, Madame De Giving's provides various examples throughout her letter using writing tools and strategies. She depicts her purpose through her diction and drama ‘zing the horrors of the Berliners woman. Her strategic organization shifts this monotonous e vent into a story of her own. Even though she takes a mo re Juvenile approach towards her though TTS , she uses elite strategies to make her purpose apparent.