Low-Voltage Ultra-Low-Power Current Conveyor Based on Quasi-Floating Gate Transistors

The field of low-voltage low-power CMOS technology has grown rapidly in recent years; it is an essential prerequisite particularly for portable electronic equipment and implantable medical devices due to its influence on battery lifetime. Recently, significant improvements in implementing circuits working in the low-voltage low-power area have been achieved, but circuit designers face severe challenges when trying to improve or even maintain the circuit performance with reduced supply voltage. In this paper, a low-voltage ultra-low-power current conveyor second generation CCII based on quasi-floating gate transistors is presented. The proposed circuit operates at a very low supply voltage of only ±0.4 V with rail-to-rail voltage swing capability and a total quiescent power consumption of mere 9.5 µW. Further, the proposed circuit is not only able to process the AC signal as it's usual at quasi-floating gate transistors but also the DC which extends the applicability of the proposed circuit. In conclusion, an application example of the current-mode quadrature oscillator is presented. PSpice simulation results using the 0.18 µm TSMC CMOS technology are included to confirm the attractive properties of the proposed circuit

Theoretical study of photorefractive effect in reduced potassium niobate crystals

Study of photorefractive properties for reduced potassium niobate was performed with using a band model for one impurity center, Which is allowed to study the photoconductivity, to calculate the light induced absorption, to study the space charge field and the exponential gain in the absence of the applied field, as function of the light intensity, the wavelength and the grating spacing. It also allows to study the exponential gain and the phase appear between the space charge field and the illumination as function of the applied field.Study of photorefractive properties for reduced potassium niobate was performed with using a band model for one impurity center, Which is allowed to study the photoconductivity, to calculate the light induced absorption, to study the space charge field and the exponential gain in the absence of the applied field, as function of the light intensity, the wavelength and the grating spacing. It also allows to study the exponential gain and the phase appear between the space charge field and the illumination as function of the applied field

Theoretical study of the optical dispersion and anisotropy of the oxygen polarisability of PbTiO3 in the tetragonal phase

The optical anisotropy of the tetragonal phase of PbTiO3 is discussed according to the point-dipole approach. In this microscopic model, we have taking into account of the electronic polarization and the lattice deformation, and it is shown that anisotropic electronic polarizabilities are the dominant source of the optical properties of PbTiO3 . This anisotropy is attributed to the Oz oxygen ion and it is due to the Ti-Oz and Pb-Oz overlap in the tetragonal phase. By analyzing the optical refractive index data of PbTiO3 at 0.589 µm, we have determined the temperature dependence of the oxygen polarizabilities. Based on the dispersion data of the refractive index of PbTiO3 , the dispersion of the oxygen polarizabilities is similarly calculated at room temperature.The optical anisotropy of the tetragonal phase of PbTiO3 is discussed according to the point-dipole approach. In this microscopic model, we have taking into account of the electronic polarization and the lattice deformation, and it is shown that anisotropic electronic polarizabilities are the dominant source of the optical properties of PbTiO3 . This anisotropy is attributed to the Oz oxygen ion and it is due to the Ti-Oz and Pb-Oz overlap in the tetragonal phase. By analyzing the optical refractive index data of PbTiO3 at 0.589 µm, we have determined the temperature dependence of the oxygen polarizabilities. Based on the dispersion data of the refractive index of PbTiO3 , the dispersion of the oxygen polarizabilities is similarly calculated at room temperature

Conceptualisation and pilot study of shelled compressed earth block for sustainable housing in Nigeria

AbstractMeeting the housing needs in Nigeria is a long-standing task, yet to be realised. The economy of the country, as most developing countries, is ailing with limited resources. Energy and infrastructures are inadequate, yet the use of cement dominated the construction industry. Earth construction is a sustainable option to housing with inherent characteristics that should be desirable in the ailing economy of hot tropical environment in Africa. However, most Nigerians are skeptical of taking a low cost option with less modern effects and uncertain durability. This research explores the issues relating to this problem and aims to bridge the gap between Nigerians and earth, which exists in abundance in Africa. The emerging concept from the survey of public reaction to earth construction in Nigeria is of a shelled compressed earth block (SCEB) of an inner core of ‘earth’ with less stabilisation and an outer shell of the same earth composition but with higher ratio of cement stabilisation for adequate durability, compressed into a single piece. A mechanical kit was designed and fabricated for the production of sample shelled compressed earth block for laboratory tests. Basic preliminary tests were conducted on the model and results revealed that the concept was feasible thus paved the way for further research work in shelled compressed earth block (SCEB)

A System Dynamics Model to Predict Municipal Waste Generation and Management Costs in Developing Areas

This paper utilized system dynamics modeling as a new analytical approach to predict both the municipal waste generated and the associated disposal costs in developing areas. This approach facilitates the decomposition of general waste into its main components to enable municipalities to manage recyclables and find out the feasibility of performing recycling better rather than disposal by performing comparative disposal cost analysis. This study is different from previous work as it only considers population as a factor to predict the total waste generated and recycled, together with the associated expenditure and disposal cost savings. The approach is verified by applying it to a case study in Nablus and demonstrates the evaluation of the quantity and composition of generated waste by considering population as the main influencing factor. The quantity and composition of municipal solid waste was evaluated to identify opportunities for waste recycling in the Nablus municipality. Municipal solid waste was collected and classified into eight main physical categories. The system dynamics model enable the quantity of each generated component such as plastic and metals to be anticipated together with the cost of recycling or disposal

Double precision trajectory program /DPTRAJ 2.2C/

Four part program computes trajectory of space probe moving in solar system and subject to variety of forces

A Simple Reactive Obstacle Avoidance Algorithm and Its Application in Singapore Harbor

Autonomous surface craft (ASC) are increasingly attractive as a means for performing harbor operations including monitoring and inspection. However, due to the presence of many fixed and moving structures such as pilings, moorings, and vessels, harbor environments are extremely dynamic and cluttered. In order to move autonomously in such conditions ASC’s must be capable of detecting stationary and moving objects and plan their paths accordingly. We propose a simple and scalable online navigation scheme, wherein the relative motion of surrounding obstacles is estimated by the ASC, and the motion plan is modified accordingly at each time step. Since the approach is model-free and its decisions are made at a high frequency, the system is able to deal with highly dynamic scenarios. We deployed ASC’s in the Selat Pauh region of Singapore Harbor to test the technique using a short-range 2-D laser sensor; detection in the rough waters we encountered was quite poor. Nonetheless, the ASC’s were able to avoid both stationary as well as mobile obstacles, the motions of which were unknown a priori. The successful demonstration of obstacle avoidance in the field validates our fast online approach.Massachusetts Institute of Technology. Singapore-MIT Alliance in Research and Technology (SMART

Brief of \u3cem\u3eAmicus Curiae\u3c/em\u3e Interdisciplinary Research Team On Programmer Creativity In Support Of Respondent

This brief answers the two primary issues that are associated with the first question before the Court. First, the programmers’ expression of the Java-based application programmer interfaces (“APIs”) are sufficiently creative to satisfy that requirement of copyright law. Second, the idea expression limitation codified in Section 102(b) of Copyright Act does not establish that the APIs are ideas. Both of these assertions are supported by the empirical research undertaken by the Research Team. This brief expresses no opinion on the resolution of the fair use question that is also before the Court

Reducing the burden of obesity-associated cancers with anti-inflammatory long-chain omega-3 polyunsaturated fatty acids

Today’s world population has an unprecedented risk of dying from the consequences of being overweight and obese. Chronic diseases such as cardiovascular disease, type 2 diabetes, and cancer are often accelerated because of excessive adiposity. Various biological mechanisms are implicated in the obesity-cancer link, particularly local and systemic inflammation as well as altered growth factor signaling pathways. In order to combat obesity-induced inflammation and the resulting increases in cancer risk and progression, the identification of safe and effective mechanism-based interventions is imperative. Notably, long chain omega-3 polyunsaturated fatty acids (PUFAs) modulate the secretion of pro-inflammatory cytokines, prostaglandins and other inflammatory mediators, restore insulin sensitivity, and can prevent or delay tumorigenesis. Delineating the precise mechanisms by which omega-3 PUFAs suppress obesity-induced inflammation will help identify promising key mechanistic targets and intervention strategies to break the obesity-cancer link