In this paper we extend the exponential sum results from [B-K] and [B-G-K] for prime moduli to composite moduli q involving a bounded number of prime factors. In particular, we obtain nontrivial bounds on the exponential sums associated to multiplicative subgroups H of size q, for any given δ > 0. The method consists in first establishing a ‘sum-product theorem’ for general subsets A of Z. If q...

We have developed a novel mediated biochemical oxygen demand (BOD) biosensor based on immobilized Bacillus subtilis (B. subtilis) on three-dimensional (3D) porous graphene-polypyrrole (rGO-PPy) composite. The 3D porous rGO-PPy composite was prepared using hydrothermal method following with electropolymerization. Then the 3D porous rGO-PPy composite was used as a support for immobilizing negativ...

Understanding how disturbance affects biodiversity is important for both fundamental and applied reasons. Here, I investigate how disturbances with different ecological effects change biodiversity metrics. I define three main types of disturbance effects: D disturbance (shifts in mortality rate), B disturbance (shifts in reproductive rates) and K disturbance (shifts in carrying capacity). Numer...

Objective. To investigate the pattern of cognitive impairment in relapsing remitting multiple sclerosis (RRMS) and secondary progressive multiple sclerosis (SPMS) patients using a computerized battery. Methods. RRMS patients (N = 50), SPMS patients (N = 30), and controls (N = 31) were assessed by Central Nervous System Vital Signs (CNS VS) computerized battery, Trail Making Tests (TMT) A and B,...

PURPOSE The aim of this study was to evaluate the effects of 4 mouth rinses on the color stability of two different resin composites. MATERIALS AND METHODS A2 shade sonic-activated bulk fill material SonicFill (Kerr) and conventional nanohybrid composite Filtek Z550 (3M ESPE) were used. Forty disc-shaped specimens (10 mm x 2 mm) were fabricated for both composites and finished using 400-grit ...

A finite element model is constructed to analyze the steady heat conduction and thermal stress in a ceramic/FGM/metal composite EFBF plate under convective heat transfer boundary. From numerical calculation, when 1   b a   , T0=Ta =300K and Tb=1 800K, the steady heat conduction and thermal stress distributions in the plate were obtained. The numerical results show that the temperature distr...

Volume fraction of fibres (A), aspect ratio of fibres (B) and fibres orientation (C) are considered as control factors in the determination of hardness strength, hardness strength of plantain fiber reinforced polyester composites (PFR P). These properties were determined for plantain empty fruit bunch (PEFB) and plantain pseudo stem (PPS). Hardness tests were conducted on the replicated samples...