Open Access Original Research Article

The Effects of Genotype and Irrigation Regime on PSII Heat Tolerance in Cotton

Cristiane Pilon, John L. Snider, Derrick M. Oosterhuis, Dimitra Loka

Advances in Research, Page 1-11
DOI: 10.9734/AIR/2016/22632

Aims: Differences in tolerance to drought and heat stresses exist among cotton species and between modern and obsolete genotypes. However, it is not clear if increases in thermostability under water deficit are associated with genotypic differences in drought tolerance. Therefore, the objective was to identify differences in heat tolerance and physiological acclimation of contrasting cotton genotypes under water-deficit stress and recovery conditions.

Study Design: The experimental design was a randomized complete block design with five replications. Treatments consisted of three cotton genotypes, DeltaPine (DP) 0912 B2RF, Pima 32, and Siokra L23 and two water regimes, a well-watered control and a water-stressed treatment.

Place and Duration of Study: The experiment was conducted in 2012, and repeated in 2013, at the Altheimer Laboratory, University of Arkansas in Fayetteville, Arkansas.

Methodology: Heat tolerance was assessed through maximum quantum yield of Photosystem II at temperatures 25°C to 45°C and measurements of stomatal conductance were also performed.

Results: Differences (P = .05) in heat tolerance and physiological acclimation exist among the genotypes under water-deficit stress and recovery conditions. Pima 32 showed higher heat tolerance and improved stomatal conductance at recovery. Siokra L23 was relatively heat sensitive and showed moderate recover in stomatal conductance after plants were re-watered. DP 0912 was the least heat tolerant.

Conclusion: Thermostablity under water-deficit stress was associated with drought tolerance of genotypes, with Pima 32 having the highest heat tolerance acclimation in response to water-deficit stress, followed by Siokra L23 and DP 0912.

Open Access Original Research Article

PID Control Design of Sideslip Angle for a Fixed-Wing Mini-UAV

B. K. Aliyu, A. A. Petinrin, J. A. Adewumi

Advances in Research, Page 1-14
DOI: 10.9734/AIR/2016/22738

Sideslip angle is one of the state variables in the lateral state-space dynamics of an Unmanned Aerial Vehicle (UAV). Large asymmetric aerodynamic loads can be induced on a UAV’s fuselage, even at zero sideslip. For steady and level flight, this angle must be controlled. To control the sideslip angle, a mathematical model for the UAV is required using static and dynamic aerodynamic as well as cross-term coefficients. Aircraft Digital Datcom was used to estimate the UAV’s aerodynamic coefficients, aerodynamic stability and control derivatives from its physical geometry. The challenge for a control engineer is the choice of transfer function (plant) to be used for sideslip angle controller design in an autopilot system. Since both the lateral model and it reduced form; Dutch Roll (DR) approximated model have sideslip angle as a state variable. In this study, the pitch plane is ignored as well as cross-terms in the moments of inertia. Dutch Roll is focused upon firstly; we investigated the dynamics characteristics of both models. Secondly, sideslip angle transfer functions obtained from both the lateral and DR approximated models were compared. The eigenvalues, natural frequencies, damping ratio, period and number of cycle to damp to half amplitude of the Dutch roll mode in the lateral dynamics are about the same with those of the Dutch roll approximated model. Steady state values and open-loop step responses computed in MATLAB & Maple differ in magnitude and direction on the Cartesian plane. Despite the limitations of this initial effort, Proportional-Integral-Derivative (PID) controllers were designed in MATLAB/Simulink for all transfer functions. Design results analysed gives intuitive and informed design choice for autopilot gains for the sideslip angle control.

Open Access Original Research Article

Mathematical Analysis of a Class of Surface-Tension Driven Flows

Yuh-Yih Chen, Jenn-Tsann Lin, Hsiu-Chuan Wei

Advances in Research, Page 1-8
DOI: 10.9734/AIR/2016/22415

In this paper, a two-point boundary value problem arising from a class of surface-tension driven
flows is considered. The existence properties of solutions are established, and all possible solutions
are classified using mathematical analysis. The problem possesses unique or multiple solutions
depending on parameter values. Bifurcation diagrams are computed to verify the results obtained
by mathematical analysis.

Open Access Original Research Article

A Study on Meromorphic Harmonic Starlike Functions by Using a New Generalized Differential Operator

F. Muge Sakar, H. Ozlem Guney

Advances in Research, Page 1-8
DOI: 10.9734/AIR/2016/23045

In this study, a new generalized differential operator D was obtained first.Then this new differential
operator was used to introduce a new class GS(n) of univalent meromorphic harmonic starlike
functions exterior to the unit disc eU
:= {z |z| > 1}. Especially, coefficient bounds for this class have
been examined. This coefficient condition is also necessary for the class GS(n) which is subclass
of meromorphic harmonic functions. Furthermore, some other properties such as distortion
theorems and extreme points for these classes were obtained and relevant results were given.

Open Access Original Research Article

Processing and Seebeck Effect Measurement of a Bismuth Based Alloy

Johann Van Bel, Christopher Tong, Ryan N. Gan, Manuel Eshaghof, Chris-Dominique N. Nsavu-Nzau, Yong X. Gan

Advances in Research, Page 1-6
DOI: 10.9734/AIR/2016/23400

The objective of this work is to develop a casting manufacturing process to produce a bismuth-based porous material. Induction heating was applied to melt Bi-Sn alloy in a quartz tube and the molten alloy was cast into loosely compacted sodium chloride powder. After the sodium chloride powder was dissolved by water, pores were generated in the Bi-Sn alloy. The true porosity of the alloy can be controlled as high as 58.7% in volume. The thermoelectric property of the material has been studied to explore the application of this material for energy conversion. The experimental results show that the Seebeck coefficient of the porous bismuth material is independent of porosity. The porosity of the material can be controlled through manufacturing parameters. The higher the porosity is, the slower the heat conduction in the material.

Open Access Original Research Article

Fast Screening Method for Detecting Lysine-producing Yeasts

L. O. Chike-Mozie, C. C. Ekwealor, T. C. Ajogwu, C. Chibor-Ekweanya, I. A. Ekwealor

Advances in Research, Page 1-4
DOI: 10.9734/AIR/2016/21988

Aim: To screen for active Lysine -producing yeasts.

Study Design: Examination of different kinds of fruits.

Place and Duration of Study: Department of Applied Microbiology and Brewing, Nnamdi Azikiwe University, Awka, from January, 2014 and July, 2015.

Methodology: Yeast isolates (100) recovered from different fruits were screened for lysine producers on solid agar medium. Halo growth of the lysine auxotroph, Escherichia coli, seeded in the agar medium indicate lysine production by the yeast isolate. Lysine accumulation in submerged medium by the isolate was examined.

Results: Five of the yeast isolates observed to be active lysine producers accumulated lysine yields of 0.20 µg/ml to 0.90 µg/ml in submerged medium. The lysine level accumulated in the broth culture of the yeast was observed to be proportional to the halo growth of the Escherichia coli on solid agar medium.

Conclusion: Yeasts capable of producing lysine were isolated from fruits and a fast screening method for their detection on solid agar medium have been identified.

Open Access Original Research Article

Effect of Biological Control Antagonists Adsorbed on Chitosan Immobilized Silica Nanocomposite on Ralstonia solanacearum and Growth of Tomato Seedlings

Gatahi Dennis, Wanyika Harrison, Kihurani Agnes, Gatebe Erastus

Advances in Research, Page 1-23
DOI: 10.9734/AIR/2016/22742

Background: Biological control holds promise in managing bacterial wilt disease. However, its efficacy is limited by harsh environmental conditions when applied without use of suitable carrier materials.

Aim: The study entailed synthesis of nanocarrier materials for biological control agents (BCAs) using Chitosan and silica nanocomposites.

Site and Duration: The experiments were carried out at Jomo Kenyatta University of Agriculture and Technology for a period of two years June 2013 to June 2015.

Methodology: The experiments were conducted using a completely randomized design with three replications. Deacetylation, functionalization and immobilization of chitin on mesoporous silica nanoparticles (MSN) to form chitosan immobilized silica nanocomposites (CISNC) gel was done.

Results: This resulted in formation of chitosan nanoparticles and CISNC with crystallite sizes of 2.8 and 4.4 nm respectively. BCAs were adsorbed on CISNC gel. Characterization of the bio-nanocomposites showed that they had physisorption properties thus, ideal carriers for BCAs. CISNC gel had the highest significant (P=.05) sorption properties with 75% and 65% adsorption and desorption respectively of BCAs. Efficacy trials were done by in vitro pathogen inhibition and greenhouse bioassays using tomato seedlings. Adsorption of BCAs on CISNC gel significantly (P=.05) increased inhibition efficacy of BCAs on R. solanacearum from 50 to 70%. This was attributed to the antibacterial effect of the individual substances and the overall synergy acquired. Further, BCA-CISNC gel forms a film around root hairs, initiates fast wound healing mechanism and induce prophylactic effect on tomato seedlings challenged with R. solanacearum pathogen, decreasing wilting incidences from 45 to 25%. Additionally, BCA-CISNC complex significantly (P=.05) increased tomato seed germination from 70 to 80% and growth rate from 12 to 15% due to enhanced water utilization efficiency, induced phytohormones and nutritional benefit. BCAs also aided faster nutrient release, absorption and utilization by tomato plants.

Conclusion: Therefore, adsorption of bacterial, fungal and phage biocontrol agents on CISNC gel, a complex hitherto not reported to have been used in R. solanacearum disease control, enhanced microbial efficacy against the pathogen and increased tomato productivity.

Open Access Review Article

Pharmacopoeial Standards and Specifications for Pharmaceutical Aerosols: In-Process and Finished Products Quality Control Tests

Md. Sahab Uddin, Mahbubul Hossain, Abdullah Al Mamun, Sonia Zaman, Md. Asaduzzaman, Mamunur Rashid

Advances in Research, Page 1-12
DOI: 10.9734/AIR/2016/22442

Pharmaceutical aerosol is a pressurized system that depends on the power of a compressed or liquefied gas to expel the contents from the container. Therapeutic performance of pharmaceutical aerosols is affected by various factors such as actuator tube design, orifice diameter, concentration of surfactant in the system, moisture content and deposition of emitted dose, vapor pressure of propellants, spray pattern, efficiency of valve crimping and measurement of particle size aerosols. Unique feature of this dosage form is the presence of propellants, whose properties like flash point, viscosity and density and presence of active ingredients, containers, valves and actuators also modify the aerosol performance. A pharmaceutical aerosol must satisfy certain standards to claim it to be a quality drug. The main standard for the quality of any drug is the intrinsic and extrinsic elements which contribute directly or indirectly to the safety, potency, efficacy, stability, patient acceptability and regulatory compliance of the products. In process quality control (IPQC) tests are performed in order to remove error from every stage in production. After the manufacturing process is complete finished product quality controls (FPQC) test are performed with respect to the specification of the pharmacopoeias with a view to checks that the quality parameters are within the acceptable limits or not. So, the total quality of pharmaceutical aerosols depends on both IPQC and FPQC tests. The objective of this study is to provide various in-process and finished product quality control tests for pharmaceutical aerosols as per pharmacopoeial standards and specifications.