Short Cycle Period Research Articles

Butterfly-tie like MnCO3@Mn3O4 heterostructure enhanced the electrochemical performances of aqueous zinc ion batteries

Due to the limited exploitation and utilization of fossil energy resources in recent years, it is imperative to explore and develop new energy materials. As an electrode material for batteries, MnCO3 has the advantages of safety, non-toxicity, and wide availability of raw materials. But it also has some disadvantages, such as short cycle period and low conductivity. In order to improve these deficiencies, we designed a MnCO3@Mn3O4 heterostructure material by a simple solvothermal method, which possessed a microstructure of “butterfly-tie”. Owing to the introduction of Mn3O4 and the layered structure of “butterfly-tie”, MnCO3@Mn3O4 possessed a discharge capacity of 165 mAh/g when the current density was 0.2 A/g and exhibited satisfactory rate performance. The MnCO3@Mn3O4 heterostructure was optimized by density functional theory (DFT), and the deformation charge density was calculated. It was found that the MnCO3@Mn3O4 heterostructure is stable owing to the molecular interaction between the O atoms from MnCO3 and the Mn atoms from Mn3O4 at the interface of heterojunction. Therefore, the MnCO3@Mn3O4 heterostructure material has promising applications as safe and efficient cathode material for energy batteries.

Impact of Jhum Cultivation on Forest Ecosystem and Environment Management Policies in Meghalaya, India

Shifting or jhum cultivation is one of the primary causes of deforestation in tropical areas. In Meghalaya, increasing human population density like in other states of India has resulted in the practice of unsustainable form of jhum that includes shortening of the fallow period of jhum cycle. This unsustainable form of jhum cultivation leads to soil degradation, soil erosion, loss of forest vegetation and threatens the survival of valuable flora and fauna. The study area is one of the richest reservoirs of plant diversity of North-East India as well as India. The decreasing fallow period from 15-20 to 2-3 years has a negative impact on the environment sustainability in Meghalaya which reduced the quality of soil. The overall reduction in the forest, mainly due to jhumming can severely affect the viable forest habitat of the endangered fauna. This study reveals the effects of short jhum cycle period on current forest ecosystem.

A Comparative Study of Sustainable Transition from Catch-up to Post Catch-up of South Korea and China

The essence of the experience of East Asia has been on technological capability building and dynamic industrial transitions from one stage to the next. While many studies for understanding the catch-up process and post catch-up agendas exist, empirical and comparative studies that consider the transition from catch-up to post catch-up are still rare. The significance of this research can be summarized in two ways. First, this study verifies the conformity of existing major catch-up to post catch-up transition studies with quantitative evidence. Second, by comparing commonalities and patterns from South Korea and China, this study examines the generality of the discourses and arguments about the transition from catch-up to post catch-up. The reflexive study of understanding transition from catch-up to post catch-up was conducted with a technology cycle time (TCT), self-citation ratio at a country level, and the basic research expenditure of Korea and China by using the US Patents and Trademark Office’s (USPTO) patent citation (for technology cycle time & self-citation ratio) and OECD’s database (basic research expenditure and gross domestic expenditure on basic research) for time period from 1998 to 2012. Empirical evidence of technology cycle time, self-citation ratio and gross domestic expenditure on basic research matched well with the prior transition arguments. First, Korea’s case shows a post catch-up trend with an increasing technology cycle time while China’s case presents catch-up trend (short-cycle period) and shifts to post catch-up trend (post catch-up trend). Self-citation ratios for both countries show increasing and converging pattern. In terms of basic research activities, both countries show increasing pattern. Korea exceeded the gross domestic expenditure on basic research of Japan and the US. Even though, China’s gross domestic expenditure on basic research has been tripled from 1998 to 2012, China’s gross domestic expenditure on basic research has still a long way to go to close the gap and to show a converging pattern. Many developing countries that once experienced a certain level of successful catch-up did not overcome the middle income trap have fallen behind. Understanding transition process of catch-up to post catch-up discussed in this paper may present a better understanding of long-term sequential development and economic sustainability of developing countries.

Analysis of energy consumption and latency in advanced wireless networks through DRX mechanism

Ever-increasing need for high data rate and wide penetration of subscriber base are the need for the constant evolution of transmission of mobile traffic data. The global mobile-manufacturing industry is growing rapidly. Energy consumption by wireless communication systems is a vital concern in the present world, not merely to reduce energy consumption but also to mitigate environmental degradation due to effluence caused by extreme energy consumption. While Long Term Evolution-Advanced (LTE-A) method is a standardized fourth-generation portable communication tool for the compelling demands for rapid wireless communication, the extreme energy consumption during the high-speed processing signal on LTE-A user equipment (UE) is a key concern to be addressed for its effective implementation. The discontinuous reception (DRX) based on two contradicting parameters, namely energy consumption and latency, can be optimized for the efficient utilization of UE with optimal energy consumption. Stochastic-based Markov model has been selected to model the randomly changing communication process. The present study analyses the influence of arrival rate, short cycle, long cycle and timer value of short cycle on energy consumption. The present analysis is also focused to build up a systematic model to estimate latency and energy-saving utilized by DRX method for active mobile data traffic. The results indicate that short cycle period of DRX is very effective in reducing latency for active data traffic, and optimal selection of values for various operating parameters can maintain low latency in addition to considerable energy-saving.

Restoration performance and operation characteristics of a vertical U-tube ground source heat pump system with phase change grouts under different running modes

This work investigates the effects of different operation modes on the restoration performance and operation characteristics of a ground source heat pump (GSHP) system backfilled with phase change materials (PCM). A numerical GSHP system model considering site conditions and dynamic loads was developed and validated. The effects of daily working schedules, load features and operation schedules of short time period operation modes, and phase-transition temperature of PCM grout were explored. The results show that PCM grout is more suitable for buildings with less-persistent thermal demand considering the importance of restorability. Operating the GSHP with cooling & heating alternate load is the most effective way to improve the overall performance of the system, but a suitable operation schedule should be used. Decreasing the cycle ratio is the best method to promote the system performance under the same hourly load intensity, while for the operation schedules with higher hourly load intensity, a shorter cycle period is recommended. The phase-transition temperature of PCM grout influences the system stability and sustainability greatly as it controls when the melting occurs. The grout with the phase-transition temperature of 20.4 °C is demonstrated to be the most suitable one under our conditions as it provides relatively stable and effective performance over the entire summer and has a higher utilization ratio of the latent heat.

Latitudinal migration of sunspots based on the ESAI database

The latitudinal migration of sunspots toward the equator, which implies there is propagation of the toroidal magnetic flux wave at the base of the solar convection zone, is one of the crucial observational bases for the solar dynamo to generate a magnetic field by shearing of the pre-existing poloidal magnetic field through differential rotation. The Extended time series of Solar Activity Indices (ESAI) elongated the Greenwich observation record of sunspots by several decades in the past. In this study, ESAI’s yearly mean latitude of sunspots in the northern and southern hemispheres during the years 1854 to 1985 is utilized to statistically test whether hemispherical latitudinal migration of sunspots in a solar cycle is linear or nonlinear. It is found that a quadratic function is statistically significantly better at describing hemispherical latitudinal migration of sunspots in a solar cycle than a linear function. In addition, the latitude migration velocity of sunspots in a solar cycle decreases as the cycle progresses, providing a particular constraint for solar dynamo models. Indeed, the butterfly wing pattern with a faster latitudinal migration rate should present stronger solar activity with a shorter cycle period, and it is located at higher latitudinal position, giving evidence to support the Babcock-Leighton dynamo mechanism.

Thermodynamic analysis of heat transfer in a wellbore combining compressed air energy storage

Compressed air energy storage (CAES) is a potential energy storage technology. The gas phase and short cycle period are two key factors affecting heat transfer loss in the wellbore of CAES. A semi-analytical solution was developed by using the convolution method considering gas movement in this study to describe the transient behavior of heat transfer with a short cycle period. The comparative analysis of the presented solution with two published solutions showed that the solution matched well with the previous solutions under steady state. Parametric studies were carried out to investigate the impact of injection rate, overall heat transfer coefficient and thermal diffusivity of the formation on heat loss in the wellbore. The results indicated that a low overall heat transfer coefficient and thermal diffusivity of the formation with an appropriate injection rate can efficiently reduce the heat loss. A hypothetical case study with a short cycle period of injection and production was conducted to demonstrate the applicability of the developed solution in CAES. The results suggest that the semi-analytical solution is applicable for heat transfer in the wellbore of CAES.

Advanced Accelerated Power Cycling Test for Reliability Investigation of Power Device Modules

This paper presents an apparatus and methodology for an advanced accelerated power cycling test of insulated-gate bipolar transistor (IGBT) modules. In this test, the accelerated power cycling test can be performed under more realistic electrical operating conditions with online wear-out monitoring of tested power IGBT module. The various realistic electrical operating conditions close to real three-phase converter applications can be achieved by the simple control method. Further, by the proposed concept of applying the temperature stress, it is possible to apply various magnitudes of temperature swing in a short cycle period and to change the temperature cycle period easily. Thanks to a short temperature cycle period, test results can be obtained in a reasonable test time. A detailed explanation of apparatus such as configuration and control methods for the different functions of accelerated power cycling test setup is given. Then, an improved in situ junction temperature estimation method using on-state collector–emitter voltage $V_{{\rm CE}\_{\rm ON}}$ and load current is proposed. In addition, a procedure of advanced accelerated power cycling test and test results with 600 V, 30 A transfer molded IGBT modules are presented in order to verify the validity and effectiveness of the proposed apparatus and methodology. Finally, physics-of-failure analysis of tested IGBT modules is provided.

A Column-Parallel Inverter-Based Cyclic ADC for CMOS Image Sensor With Capacitance and Clock Scaling

This paper presents a low-power column-parallel inverter-based cyclic analog-to-digital converter (ADC) for CMOS image sensor readout circuit. By partially floating the capacitors inside the multiply digital-analog-converter during the least significant bit (LSB) quantization, the amplifier load capacitance could be significantly scaled down, which allows much higher settling speed and shorter cycle period. Since the signal-to-noise ratio for LSB cycle is relaxed due to the residual amplification, the proposed capacitance scaling only contributes ignorable input-referred quantization noise. Using the proposed techniques, a cyclic ADC can operate under 50% power consumption without suffering conversion rate, noise performance, and linearity. A 12-b quantization resolution test chip is fabricated using the TSMC 0.18-μm technology with 110 column-parallel ADC channels and 10.08-μm × 750-μm column pitch. The 3.5/-2 LSBs integral nonlinearity and 10.1-b effective-number-of-bit are measured under 2-μs sampling rate with 120-μW power consumption per channel.

Dental ontogeny and replacement in Pliosauridae.

Dental morphology and patterns of tooth replacement in representatives of the clade Pliosauridae (Reptilia, Sauropterygia) are evaluated in detail. The jaws of one basal (Thalassiodracon hawkinsii) and two derived species (Pliosaurus carpenteri, Pliosaurus kevani) were visualized by μCT scans, and the ontogenetic patterns, or ‘movement paths’, of replacement teeth could be mapped. Other specimens (Peloneustes philarchus and Pliosaurus westbuyensis) with well-preserved jaws containing functional and replacement teeth in situ were also examined directly, and waves of tooth replacement could be inferred from the degree of in situ tooth development and the fusion between functional and replacement alveoli. The analysis revealed symmetrical tooth eruption over the medial axis throughout the length of the jaw in the basal pliosaurid Thalassiodracon. By contrast, symmetrical tooth eruption patterns occur only along the anterior sections of the jaws of derived pliosaurids. In Pliosaurus, replacement schedules differ in the anterior and posterior portions of the jaws and appear to correlate with differences in tooth morphology and symmetrical replacement. The anterior teeth exhibit longer replacement cycle periods and symmetrical replacement, while shorter cycle periods and asymmetry are seen posteriorly. A longer period suggests slower replacement and is characteristic of large, specialized caniniform teeth in the longer snouted Late Jurassic taxa. Smaller posterior teeth have a shorter period and therefore a faster replacement cycle. The transition from long to short replacement period over the length of the jaw is thought to account for the loss of symmetry. This differentiation could relate to differential tooth function and a type of heterodonty. We therefore propose a new model of pliosaurid tooth replacement patterns and present it in a phylogenetic context.

공동주택 주호개수를 위한 거주자 참여 디자인 수법에 관한 사례연구

Apartments amount to 58.3%, the highest proportion of domestic housing types. These apartments' lifespan (approximately 27 years) are one-third of the developed countries' housing lifespan due to the property developers and mass production. It is significantly short-cycle period considering the original physical lifespan of the apartment housing are 60 years. It has caused economic loss and environmental degradation. In recent years, research and development for the long life of the apartment housing has been actively performed, but it is limited on reconstruction and new construction. Reconstruction of existing a number of high-rise apartments is difficult owing to restrictions on the floor area ratio allowing for 40 years limit of decay resistance after the completion. Improving lifespan of the building has recently begun to receive attention as an alternative to remodeling. However, These sort of remodeling techniques tend to be focused on technology developed for the physical life extension. That means developing the techniques about dwelling-unit environment for residents satisfaction are required as well as improving physical construction. The purpose of this study is to propose and verify the Participatory Design Technique which can help the residents as the active participation in the design decision-making process.

Comparative Studies on Vegetable Oil Usage in C.I Engines as an Alternative to Diesel Fuel

The rising energy needs resulting from increased claim and diminishing supply, alternative energy sources are receiving more attention. In addition, the increasing global concern has caused to focus on the oxygenated diesel fuels because of the environmental pollution from internal combustion engines. Vegetable oils possess almost the same heat values as that of diesel fuel with inherently high viscosity. Vegetable oil is easily available, renewable fuel with short carbon cycle period and is environment friendly. These are the triggering factors for research all over the world to consider vegetable oils and their derivatives as alternative to petroleum diesel. Researchers experimented that vegetable oil fuelled engine power output and fuel consumption are comparable to diesel when fuelled with vegetable oil and its blends and produce less carbon monoxide (CO), unburned hydrocarbon (HC), and particulate emissions compared to mineral diesel fuel but higher NOx emissions than that of pure diesel fuel. This paper reviews the various production techniques, properties of vegetable oil and its biodiesel along with the challenges faced and experiments carried out by various researchers around the world.

Reproductive characteristics of the female laboratory rat

The laboratory rat is widely used in research studies as a model of mammalian health and disease. This review provides the basic facts about female rat reproduction and highlights the reproductive characteristics which make the rat a preferred animal model for research on reproduction. Rats have short estrous cycle, lasting four to five days. The estrous cycle consists of four stages known as proestrus, estrus, metestrus and diestrus. Phases of the estrous cycle can be detected by observing behavioral changes or examining vaginal cytology. Detection of sperm in vaginal smear is an excellent predictor of pregnancy in rats. Implantation is initiated on day 5 and completed by day 7 of pregnancy. Gestation takes 21 to 23 days from copulation to parturition. Short estrous cycle and gestation period make the rat an ideal animal model for research on reproduction. Key words: Rat, estrous cycle, pregnancy detection, fertilization, embryonic development, implantation, gestation, weaning.

Matéria seca e acúmulo de macronutrientes na parte aérea das plantas de Crambe

O crambe (Crambe abyssinica) tem bom potencial para produção de biodiesel pelo seu teor de óleo, além de ser uma alternativa para a rotação de culturas. Contudo, são escassas as informações sobre a demanda de nutrientes pelo crambe. O trabalho objetivou determinar a produção de matéria seca e o acúmulo de macronutrientes na parte aérea das plantas de crambe, em diferentes estágios de crescimento e desenvolvimento. O experimento foi realizado em delineamento experimental em blocos ao acaso, com cinco repetições. Foram coletadas amostras da parte aérea das plantas aos 14, 28, 42, 56, 70 e 84 dias após a emergência (DAE). Para cada coleta, as plantas foram dividas em folha (limbo e pecíolo), caule + ramos e frutos (cápsulas) e as amostras foram secas até peso constante para posterior determinação da matéria seca e teores de N, P, K, Ca, Mg e S. As folhas apresentam grande contribuição na produção de matéria seca nas fases iniciais de desenvolvimento das plantas. A partir do florescimento, a queda das folhas é acentuada e a contribuição dos caules+ramos é maior. Foi observada a seguinte demanda pelos nutrientes na parte aérea: N>Ca>P>S>K>Mg. Quanto às quantidades exportadas via colheita de grãos, seguiu-se a ordem: N>P>S>Mg>Ca>K. A produção de matéria seca da parte aérea das plantas e dos frutos é baixa. No entanto, em função do ciclo curto e da rápida transição entre as fases de florescimento e maturação dos frutos, a adubação de semeadura é fundamental para obtenção de rendimentos satisfatórios.

Catalytic performance improvement of styrene hydrogenation in trickle bed reactor by using periodic operation

We investigated the catalytic performance improvement of styrene hydrogenation in a trickle bed reactor by using periodic operation. The effects of cycle period and split on relative conversion, which is defined as styrene conversion obtained from periodic operation over that from steady state operation, were examined at various operating conditions including gas and average liquid flow rates, pressure and temperature. The experimental results reveal that both cycle period and split have strong influence on the catalytic performance. The fast mode (short cycle period) is a favorable condition. The improvement by the periodic operation becomes less pronounced for operations at high average liquid flow rate, pressure and temperature. From this study, a maximum improvement of styrene conversion of 18% is observed.

A new intraparticle mass transfer rate model for cyclic adsorption and desorption in a slab, cylinder or sphere

A new intraparticle mass transfer rate model for cyclic adsorption and desorption in a slab, cylinder or sphere is proposed on the basis of the asymptotic behaviors of the adsorption rate for short and long cycle periods. Through comparison with the exact solution and the linear driving force (LDF) model, the new model is shown to provide a very good approximation for the instantaneous amount adsorbed as well as the adsorption rate for dimensionless half-cycle period τc=0.001∼1 and is much better than the LDF model.

Visual Experiments of Bubble Growth and Departure at the Tip of Inclined Capillary Tubes in a Stagnant Liquid

The bubble growth and departure at the tip of inclined glass capillary tubes in stagnant fluid is experimentally investigated by using a high-speed visual system. The visual experiments show that the bubble growth experiences a sphere-like growth stage and the asymmetric growth stage at the tip of an inclined capillary tube. In the asymmetric growth stage, the bubble firstly gets an upward deflection under action of buoyancy force and then the triple contact line of the bubble detaches from the downside of the tube tip and withdraws into the tube. In the period of bubble departure, the neck of the bubble shrinks towards the upside of the tube tip and finally breaks up at the far upper portion of inner surface edge. The incursion of liquid into the tube tip has been detected after the bubble departing from tube tip. It is found that the departure size and the growth cycle period of the bubble as well as the volume of liquid incursion into the tube are decreased with an increase in the inclined angle of the tube. A smaller inner diameter of the inclined capillary tube leads to a smaller bubble departure size and a shorter cycle period of the bubble growth.

FLR‐2, the glycoprotein hormone alpha subunit, is involved in the neural control of intestinal functions in Caenorhabditis elegans

The intestine plays an essential role in organism-wide regulatory networks in both vertebrates and invertebrates. In Caenorhabditis elegans, class 1 flr genes (flr-1, flr-3 and flr-4) act in the intestine and control growth rates and defecation cycle periods, while class 2 flr genes (flr-2, flr-5, flr-6 and flr-7) are characterized by mutations that suppress the slow growth of class 1 flr mutants. This study revealed that flr-2 gene controls antibacterial defense and intestinal color, confirming that flr-2 regulates intestinal functions. flr-2 encoded the only glycoprotein hormone alpha subunit in C. elegans and was expressed in certain neurons. Furthermore, FLR-2 bound to another secretory protein GHI-1, which belongs to a family of lipid- and lipopolysaccharide-binding proteins. A ghi-1 deletion mutation partially suppressed the short defecation cycle periods of class 1 flr mutants, and this effect was enhanced by flr-2 mutations. Thus, FLR-2 acts as a signaling molecule for the neural control of intestinal functions, which is achieved in a functional network involving class 1 and class 2 flr genes as well as ghi-1. These results are informative to studies of glycoprotein hormone signaling in higher animals.

Sensory-induced modification of two motor patterns in the crab,Cancer pagurus

Sensory input is pervasive among motor networks and continuously adapts motor patterns to changing circumstances. To elucidate common principles of sensorimotor integration, it is beneficial to characterize sensory influences on motor network operation and compare these influences between species. To facilitate such comparison, we have studied the influence of the anterior gastric receptor (AGR) - a proprioceptor that has been characterized in detail in two lobster species - on the pyloric (filtering of food) and gastric mill (chewing of food) motor patterns in the crab Cancer pagurus. AGR has a bipolar cell body in the stomatogastric ganglion; it was activated by tension increase in gastric mill powerstroke muscles. While two spike initiation zones accounted for its spontaneous activity, active membrane properties (sag potentials, spike frequency adaptation) contributed to the AGR response to current injections. When activated, AGR diminished spike activities in two pyloric motor neurons and prolonged the pyloric cycle period. Furthermore, AGR excited gastric mill protractor neurons, inhibited the retractor neuron and evoked phase-independent resetting of the gastric mill rhythm. Repetitive spike trains entrained the rhythm to both longer and shorter cycle periods. All AGR actions seemed to be mediated via at least two premotor projection neurons in the spatially distant commissural ganglia. The response of the gastric mill neurons was independent of AGR firing frequency. Our results suggest that homologous proprioceptors can elicit similar effects on motor patterns while utilizing different mechanisms. This work thus provides an initial framework for future studies to determine underlying common principles.

FLR-4, a Novel Serine/Threonine Protein Kinase, Regulates Defecation Rhythm inCaenorhabditis elegans

The defecation behavior of the nematode Caenorhabditis elegans is controlled by a 45-s ultradian rhythm. An essential component of the clock that regulates the rhythm is the inositol trisphosphate receptor in the intestine, but other components remain to be discovered. Here, we show that the flr-4 gene, whose mutants exhibit very short defecation cycle periods, encodes a novel serine/threonine protein kinase with a carboxyl terminal hydrophobic region. The expression of functional flr-4::GFP was detected in the intestine, part of pharyngeal muscles and a pair of neurons, but expression of flr-4 in the intestine was sufficient for the wild-type phenotype. Furthermore, laser killing of the flr-4-expressing neurons did not change the defecation phenotypes of wild-type and flr-4 mutant animals. Temperature-shift experiments with a temperature-sensitive flr-4 mutant suggested that FLR-4 acts in a cell-functional rather than developmental aspect in the regulation of defecation rhythms. The function of FLR-4 was impaired by missense mutations in the kinase domain and near the hydrophobic region, where the latter allele seemed to be a weak antimorph. Thus, a novel protein kinase with a unique structural feature acts in the intestine to increase the length of defecation cycle periods.