batterydata/paper-abstracts huggingface dataset:
To elucidate the mechanism of gas generation during charge–discharge cycling of a lithium-ion cell, the generated gases and passive films on the carbon electrode are examined by means of gas chromatography (GC) and Fourier transform infrared (FTIR) spectroscopy. In ethyl carbonate/dimethyl carbonate and ethyl carbonate/diethyl carbonate 1M LiPF6 electrolytes, the detected gaseous products are CO2, CO, CH4, C2H4, C2H6, etc. The FTIR spectrum of the surface of the carbon electrode shows bands which correspond to Li2CO3, ROCO2Li, (ROCO2Li)2, and RCO2Li. These results suggest that gas evolution is caused by electrode decomposition, reactive trace impurities, and electrolyte reduction. The surface of the electrode is composed of electrolyte reduction products. When 0.05M Li2CO3 is added as an electrolyte additive, the total volume of generated gases is reduced, and the discharge capacity and the conductivity of lithium-ions are increased. These results can be explained by a more compact and thin ‘solid electrolyte interface’ film on the carbon electrode formed by Li2CO3, which effectively prevents solvent co-intercalation and carbon exfoliation.
Alpha7 nicotinic acetylcholine receptor (α7 nAChR) agonists may be valuable treatments for negative symptoms and cognitive impairment in schizophrenia. Unfortunately, chronic exposure to an agonist may reduce the receptor's sensitivity. Therefore, we combined CDP-choline, a dietary source of the direct agonist choline, with galantamine, a positive allosteric modulator (PAM) of nicotinic acetylcholine receptors, to improve the efficiency of transducing the choline signal and, possibly, preserve the receptor in a sensitive state. We conducted a single-site, double-blind randomized clinical trial comparing galantamine/CDP-choline to placebos in schizophrenia patients with negative symptoms who were receiving second generation antipsychotics. Forty-three subjects received galantamine and CDP-choline or matching placebos for 16weeks. The primary outcome measure was the 5-item Marder negative-symptoms factor of the Positive and Negative Syndrome Scale (PANSS). Cognition and functioning were also assessed. Trial completion was high; 79%. There was no significant treatment effect on negative symptoms, other PANSS symptom factors, or the MATRICS Cognitive Consensus Battery. There were significant treatment effects in overall functioning and a test of free verbal recall. Three subjects discontinued treatment in the active treatment group for gastro-intestinal adverse events (AE). The most common AE for galantamine/CDP-choline was abdominal pain; for placebo it was headache and sweating. Although there was no significant treatment effect on negative symptoms, the direction of effect mirrored the effects on a cognitive measure and overall functioning. Further study of α7 nAChR agonist/PAMs is warranted in larger studies that will have greater power.
Previous work has suggested that, because writing is a late-acquired and complex skill, it may be a particularly sensitive index of language difficulties in children. Evidence in support of this view was obtained in a study contrasting 161 normally-developing control children aged from 7.5 to 13 years with 75 twin children of the same age who either had specific speech-language impairments, or were co-twins of affected children. Written narratives were elicited from children using a sequence of five photographs depicting a simple story, and were analysed for grammatical complexity and accuracy, intelligibility, and semantic content. Only 42 of the twins could spell well enough to attempt the narrative task. Some co-twins of affected children had deficits in written language, despite normal performance on oral language tests. Most children with language impairments were poor at writing, with particularly marked deficits on a measure of spelling and punctuation. Children with language impairments made a relatively high proportion of phonologically inaccurate spelling errors when compared with younger children at a similar vocabulary level. Those who did poorly on a nonword repetition test were especially likely to have poor written language. However, four children with pure speech difficulties produced age-appropriate written narratives.
Reticulated vitreous carbon (RVC) has been used as a matrix for electrodeposition of thin layers of Pd and Pd-rich Pd–Rh alloys. It was found that RVC substrate does not affect qualitatively hydrogen absorption behavior of Pd-based deposits. Similarly to thin Pd or Pd alloy layers deposited on Au wires, the α–β phase transition controls the overall rate of hydrogen absorption and desorption into/from Pd-based/RVC electrodes. The possibility of the application of these materials as phase charging–discharging systems was investigated. The values of specific pseudocapacitance, specific power and specific energy were comparable with those for supercapacitors utilizing various redox reactions.
Various composition of Na1+ x Si x Zr2P3− x O12 (x from 1.6 to 2.4), Y-doped Nasicon (Na1+ x + y Zr2− y Y y Si x P3− x O12, Na1+ x Zr2− y Y y Si x P3− x O12− y , where x = 2, y = 0.12) and Fe-doped Nasicon (Na3Zr2/3Fe4/3P3O12) were prepared by coprecipitating. Differential thermal analysis (DTA), thermogravimetry (TG), differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and impedance spectroscopy (IS) were used as experimental techniques. In order to obtain Nasicon materials free from ZrO2 admixture, the calcination of coprecipitates must be carried out in proper thermal conditions. The results of DTA, TG and XRD measurements allowed us to propose the best calcination conditions (to obtain mainly Nasicon phases – monoclinic or rhombohedral, depending on composition). Nasicon-type materials exhibit monoclinic to rhombohedral reversible structural transition, at transition temperature depending on composition (x). The influence of dopants was also studied. The DSC measurements in the temperature range RT–300 °C allowed us to determine the temperatures of this structural transition in the case of Na1+ x Si x Zr2P3− x O12, and Y-doped Nasicon. In the case of Fe-doped materials this transition was not detected. Additionally, the correlation between the composition, microstructure and electrical properties was studied.
Although there are a number of support services accessible for most family dementia caregivers, many caregivers reject available and affordable support. Previous research suggests that rejections of support services may result from insufficient fit of available services with caregivers’ unmet needs and a lack of acknowledgement of caregivers’ unmet needs and associated support services. The present study investigates (a) the number, proportion and types of caregivers’ rejection on recommended tailored support, (b) socio-demographic and clinical determinants of caregiver’s rejection of both people with dementia (PwD) and caregivers, and (c) caregivers’ health-related variables related to caregivers’ rejection.
Piezoelectric materials can be used to convert oscillatory mechanical energy into electrical energy. Energy harvesting devices are designed to capture the ambient energy surrounding the electronics and convert it into usable electrical energy. The design of energy harvesting devices is not obvious, requiring optimization procedures. This paper investigates the influence of pattern gradation using topology optimization on the design of piezocomposite energy harvesting devices based on bending behavior. The objective function consists of maximizing the electric power generated in a load resistor. A projection scheme is employed to compute the element densities from design variables and control the length scale of the material density. Examples of two-dimensional piezocomposite energy harvesting devices are presented and discussed using the proposed method. The numerical results illustrate that pattern gradation constraints help to increase the electric power generated in a load resistor and guides the problem toward a more stable solution.
Amorphous LiCoO2 thin films were deposited on the NASICON-type glass ceramics, Li1+x+y Al x Ti2−x Si y P3−y O12 (LATSP), by radio frequency (RF) magnetron sputtering below 180°C. The as-deposited LiCoO2 thin films were characterized by X-ray diffraction, scanning electron microscopy and atomic force microscope. All-solid-state Li/PEO18–Li (CF3SO2)2N/LATSP/LiCoO2/Au cells were fabricated using the amorphous film. The electrochemical performance of the cells was investigated by galvanostatic cycling, cyclic voltammetry, potentiostatic intermittent titration technique and electrochemical impedance spectroscopy. It was found that the amorphous LiCoO2 thin film shows a promising electrochemical performance, making it a potential application in microbatteries for microelectronic devices.
In this study, we have reinvestigated the thermal decomposition kinetics of iron(III) phosphate dihydrate FePO4∙2H2O in air atmosphere by TG/DTG and DTA techniques using non-isothermal experiments. The apparent activation energy Eα was determined by the differential and integral isoconversional methods and suggested that the decomposition reaction is complex and follows multi-step processes. A mathematical deconvolution technique using Fraser–Suzuki equation was applied to the DTG curves and allowed the separation of two distinct processes. The apparent activation energies determined by the isoconversional Friedman’s method were 93.05±3.80kJmol−1 and 73.41±3.14kJmol−1 for the first and second process respectively. Using Malek’s procedure for each process, the characteristics of y(α) and z(α) functions showed that the kinetic reaction follows the Johnson–Mehl–Avrami model (JMA(n)). One-dimensional nucleation and growth mechanism occurred firstly with f(α 1)=1.272(1− α 1)[−ln(1− α 1)](1−1/1.272) and pre-exponential factor A 1 =9.11×1010 min−1. After 27% of total conversion, a two-dimensional nucleation and growth mechanism becomes predominant with f(α 2)=2.306(1− α 2)[−ln(1− α 2)](1−1/2.306) and A 2 =1.28×108 min−1. It was concluded that the two decomposition processes of FePO4∙2H2O are closely interrelated and thus neglected the first process leads to incoherent results.
Though the date at which an orthopaedic implant was first used cannot be ascertained with any certainty, the fixation of bone fracture using an iron wire was reported for the first time in a French manuscript in 1775. The first techniques of operative fracture treatment were developed at the end of the 18th and in the beginning of the 19th centuries. The use of cerclage wires to fix fractures was the most frequent fixation at this time. The French Berenger-Feraud (1832–1900) had written the first book on internal fixation. However internal fixation of fractures could not become a practical method before Lister had ensured the safety of open reduction and internal fixation in the treatment of fractures. Lister is not only the father of asepsis; he also used metal wires to fix even closed fractures. The first internal fixation by means of a plate and screws was described by Carl Hansmann in 1858 in Hamburg. Nevertheless, Arbuthnot Lane (1892) and Albin Lambotte (1905) are considered to be the founders of this method, which was further developed by Sherman in the first part of the 20th century.
Objective: The comorbidity of schizophrenia and substance abuse is well documented and is remarkable for its prevalence and poor prognosis. While the etiology for this association is unknown, one possible mechanism relates to traumatic early life experiences, which have been shown to predispose individuals to both psychosis and substance abuse. Methods: Participants (N=122) who were outpatients in an inner city public mental health clinic and who were diagnosed with schizophrenia, were administered a battery of structured clinical assessments including the Childhood Traumatic Events Scale (CTES), Davidson PTSD rating scale, Hamilton Depression Rating Scale (HDRS), Positive and Negative Symptom Scale (PANSS), and assessments of medication satisfaction and side effects. Patients with schizophrenia and a history of substance abuse (N=70) were compared to patients with schizophrenia who did not have a history of substance abuse (N=52). Results: Patients with schizophrenia and a history of substance abuse had significantly higher frequency and severity of childhood traumatic events, greater PTSD symptomatology, significantly higher depression scores, and higher scores on the general subscale of the PANSS. Discussion: Our findings lend support to the notion that sensitization to stress from early life experiences may be a factor contributing to the high rate of substance abuse comorbidity in patients with schizophrenia.
The aim of this study is to determine the effect of regularly applied volleyball training on the physical fitness values of High School students. A total of 62 students from three different high schools participated in the study. The students who participated in the study were divided into two different groups; one group consisted of those who did not join in any sporting activities except for the physical education classes at school while the other group consisted of those who played in the school volleyball team in addition to the physical education classes at school. Eight tests were used derived from the EUROFIT test: flamingo, plate tapping, sit and reach, standing broad jump, handgrip, sit-ups, bent arm hang and 10 x 5m shuttle-run tests to determine the physical fitness of the students. The data obtained were interpreted using the SPSS 14.0 packet program.
In the work, multi-walled carbon nanotubes (MWCNTs) were coated uniformly onto the cotton fibers to make porous conductive cotton textile, where MWCNTs formed an electrically conductive interconnecting network. Then, a flexible, lightweight, cheap and porous composite was synthesized for electrochemical capacitors (ECs) by dispersed pseudocapacitive cobalt hydroxide well onto the conductive cotton textile sheet. Electrochemical results show that the unique flexible and porous composite owns the ability to deliver large area specific capacitance of 11.22Fcm−2 and good electrochemical stability of 4% capacity loss after 2000 cycles at high rates. Moreover, the extremely simple design and fabrication process we proposed here provide a universal and efficient approach to large-scale production of flexible, lightweight, low-cost and porous electrode for ECs application.
The entropy changes (ΔS) in various cathode and anode materials, as well as complete Li-ion batteries, were measured using an electrochemical thermodynamic measurement system (ETMS). A thermal model based on the fundamental properties of individual electrodes was used to obtain transient and equilibrium temperature distributions of Li-ion batteries. The results from theoretical simulations were compared with results obtained in experimental measurements. We found that the detailed shape of the entropy curves strongly depends on the manufacturer of the materials even for the same nominal compositions. LiCoO2 has a much larger entropy change than LiNi x Co y Mn z O2. This means that LiNi x Co y Mn z O2 is much more thermodynamically stable than LiCoO2). The temperatures around the positive terminal of a prismatic battery are consistently higher than those at the negative terminal, due to differences in the thermal conductivities of the different terminal connectors. When all other simulation parameters are the same, simulations that use a battery-averaged entropy tend to overestimate the predicted temperatures when compared with simulations that use individual entropies for the anode and the cathode, due to computational averaging.
This study measured ultrafine particle (UFP) levels and their size distributions in the Hsuehshan tunnel from August 12 to 19, 2009, using a Fast Mobility Particle Sizer. Measurement results demonstrate that traffic volume, the slope of the tunnel (downhill or uphill) and the ventilation system affected UFP levels inside the tunnel. Average UFP levels were about 1.0 × 105–3.0 × 105 particles cm−3 at normal traffic volume. A traffic jam in the tunnel could raise UFP levels to over 1.0 × 106 particles cm−3. UFP levels at the uphill bore were significantly higher than those at the downhill bore due to high UFP levels exhausted from vehicles going uphill at high engine load conditions. UFP levels eventually diluted 10–50% with fresh air from tunnel air shafts. Gas-to-particle condensation conversion markedly produced nucleation mode particles at the tunnel entrance section. Observations also showed Aitken mode particles markedly formed by coagulation growth of nucleation mode particles in the tunnel middle section and exit section. That is, the particle size distributions changed significantly inside the tunnel. Measurement results suggest that particles in the Aitken mode in the long tunnel governed UFP levels.
Sodium (Na) ion batteries are interesting candidates for replacing lithium (Li) ion batteries, primarily due to the abundance of Na in the environment. However, the performance and energy density of a Na-ion battery are inferior to those of a Li-ion battery. Organic active materials can help overcome the drawbacks associated with Na-ion batteries because of their many advantages. However, such organic polymer electrodes are subjected to a high self-discharge and low practical capacity because the polymer electrode easily dissolves in an organic electrolyte and forms an insulating layer. Therefore, in this study, we have designed a unique organic electrode in which an active polymer is encapsulated into a carbon nanotube (CNT) to form an electrode with high polymer content. The CNT is able to retain the active polymer within the electrode structure, providing an effective electronic conduction path. Moreover, the CNT can contain large amounts of active polymer and therefore exhibits superior electrochemical properties without self-discharge, making it well suited for use as a cathode material in a Na-ion battery.
CD4 testing is, and will remain an important part of HIV treatment and care in low and middle income countries (LMICs). We report the findings of a systematic review assessing acceptability and feasibility of POC CD4 testing in field settings.
Inorganic particulate film/poly(methyl methacrylate) (PMMA)/inorganic particulate film trilayer separators are prepared by means of simple dip-coating of inorganic particle layers on to both sides of PMMA thin films. The mechanical, thermal and electrochemical characteristics of the trilayer are investigated using scanning electron microscopy, a universal tensile machine, a thermal shrinkage test and a charge–discharge test. As a polymer matrix, PMMA has exceptional compatibility with the carbonate-based liquid electrolyte, which can result in improved battery/cell performance. When inorganic Al2O3 particles are used to coat the PMMA film, drawbacks associated with gel-type membranes, namely, poor dimensional stability and thermal stability are greatly improved. This inorganic trilayer membrane is believed to be an inexpensive, novel separator for application in lithium-ion batteries.
In this study, we analyzed the application of photovoltaic solar energy as a source of cathodic protection in metallic structures foundations on transmission lines towers. As preliminary studies concerning the need for cathodic protection of the structure, we have measured the resistivity of the soil, the pH and the natural corrosion potential. After the verification of the need for protection against corrosion, the cathodic protection system (CPS) was designed calculating the current to be injected, the PV system and a monitoring system. For analyzing the efficacy of the CPS, a comparison was made between the measurements done in two towers very close to each other, one with a CPS and the other acting as a witness. By comparing the loss in masses of the carbon steel coupons installed around the base of both towers and the measurements of the potentials reached due to the injected current, the efficacy of this system was experimentally demonstrated. In the protected tower, the rate of mass loss experienced a decrease by a factor equal to 2.5. Finally, the economical analysis using the LCC, showed that the usage of CPS has a significant and clear advantage regarding traditional methods.
A generalized first principles based charge–discharge model to simulate the cycle life behavior of rechargeable Li-ion batteries has been developed. The model is based on loss of the active lithium ions due to the electrochemical parasitic reaction and rise of the anode film resistance. The effect of parameters such as depth of discharge (DOD), end of charge voltage (EOCV) and overvoltage of the parasitic reaction on the cycle life behavior has been quantitatively analyzed. The experimental results obtained at charge rate of 1C, discharge rate of 0.5C, EOCV of 4.0V and DOD of 0.4 were used to validate the cycle life model. Good agreement between the simulations and the experiments has been achieved up to 1968 cycles. Simulation of a battery subjected to multiple cycling regimes has also been demonstrated.
We review herein several important aspects of surface chemistry in Li-ion batteries, and discuss the use of ionic liquids (ILs) for rechargeable Li batteries. We explored the suitability of ILs for 5V cathodes and Li-graphite anodes. Some advantages of the use of ILs to attenuate the thermal behavior of delithiated cathode materials are demonstrated. We also report briefly on a comparative study of the following cathode materials: LiNi0.5Mn0.5O2; LiNi0.33Mn0.33Co0.33O2; LiNi0.4Mn0.4Co0.2O2; LiNi0.8Co0.15Al0.05O2 and LiMnPO4, in standard electrolyte solutions based on mixtures of alkyl carbonates and LiPF6. We also discuss aging, rate capability, cycle life and surface chemistry of these cathode materials. The techniques applied included electrochemical measurements, e.g., XRD, HRTEM, Raman spectroscopy, XPS and FTIR spectroscopy. We found that ILs based on cyclic quaternary alkyl ammonium cations may provide much better electrolyte solutions for 5V cathodes than standard electrolyte solutions, while being quite suitable for Li-graphite electrodes. All the lithiated transition metal oxides studied (as mentioned above) develop unique surface chemistry during aging and cycling due to the acid-base and nucleophilic reactions of their surface oxygen anions. LiMn0.33Ni0.33Co0.33O2 has the highest rate capability compared to all the other above-mentioned cathode materials. Cathodes comprising nanometric size carbon-coated LiMnPO4 produced by HPL demonstrate a better rate capability than LiNi0.5Mn0.5O2 and LiNi0.8Co0.15Al0.05O2 cathodes. The former material seems to be the least surface reactive with alkyl carbonates/LiPF6 solutions, among all the cathode materials explored herein.
Li rechargeable cells made with structural the arrangement Li/membrane/Li x V2O5 were examined under different charge states using AC impedance, environmental scanning electron microscope (ESEM) and transmission electron microscope (TEM). These states include charged, discharged, and over-cycled. The lowest internal resistance was obtained from the cell in the charged state; the resistance increased when the cell was discharged; and the highest resistance was obtained from the cell in the over-cycled state. From the ESEM and TEM studies, it was found that the surface of the cathode was porous initially; however, it was coated with an amorphous film and porous features had also disappeared from the cell in the over-cycled state. In addition, higher concentration of aluminum was found on the surface of the cathode in over-cycled cells. The mechanisms for capacity degradation are discussed.