MODELING THE PERFORMANCE OF A BAOBAB SEED DECORTICATOR USING RESPONSE SURFACE METHODOLOGY

Decortication of baobab seed manually after soaking or roasting is time consuming, labour-intensive and uneconomical. The demand for baobab kernel as a source of protein is increasing for use as supplement for animal protein ration, for edible oil consumption and for other industrial uses. To ameliorate this problem, a baobab seed decorticator has been developed. This study therefore focused on the effects of process parameters; moisture content of seed, speed of decorticator and concave-shaft clearance on percentage clean kernel (Pck), percentage broken kernel (Pbk), percentage whole seed (Pws) and decorticating efficiency (DE), using Response Surface Methodology (RSM). In designing the experiments, Box-Behnken Design (BBD) was selected. Analysis of Variance (ANOVA) was carried out to evaluate and select the appropriate dependent (Pck Pbk, Pws and DE) and independent variables using both the F and P-values calculated at 95% confidence level (a=0.05). Mathematical models relating the process parameters to the responses were developed. The developed models were validated by comparing the predicted and actual experimental values. The selected quadratic models were adequate for predicting the performance of the developed decorticator. It was observed that a decrease in percentage clean kernel recovery would result if concave-shaft clearance and moisture content were increased. Likewise, the concave-shaft clearance had the highest positive effect while moisture content had the highest negative effect on percentage of broken kernel. All the three factors (process parameters) had positive effects on decorticating efficiency

Seismic Interpretation and Petrophysical Analysis for Evaluation of Ataga Field, Onshore Niger Delta, Nigeria

The majority of geophysical survey in hydrocarbon exploration and production sector is driven by the ability to describe reservoirs. This research is aimed at describing the interpretation and petrophysical analysis of the reservoirs in Ataga field Niger Delta using a combination of seismic and well-log data. The Ataga Field in the Niger Delta was subjected to 3-D seismic interpretation and petrophysical study to perform comprehensive structural interpretation, prospect evaluation, and volumetric calculation. Two reservoir windows “1” and “2” were identified and correlated from four wells ATA 10, ATA 11, ATA 5 and ATA 7. Detailed evaluation was done on well ATA 11 since it is the only well that has sufficient data for both qualitative and quantitative interpretation. Structural interpretation for inline 5731 revealed fifteen faults on the seismic vertical section through ATA 11, most of which are antithetic faults while the rest are synthetic faults. Top and base of each reservoir window was delineated from the well. Result of the petrophysical assessment of reservoir A, B and C for ATA 11 revealed that the porosity values range from (24 -29) % which are indicative of very good to excellent porosity value according to Rider (1996). While the permeability values range from (1887-2582) mD were obtained from the three reservioir A, B and C of ATA 11 which depict very good to excellent reservoir units. Since, .all of the wells were discovered to have hydrocarbon-bearing reservoir formations (sandstones), the integration of structural interpretation and well logs have successfully revealed that the reservoirs are mostly oil-bearing zones

Fabrication and characterization of cellulose acetate-based nanofibers and nanofilms for H2S gas sensing application

Electrospun nanofibers and solution-casting nanofilms were produced from an environmentally friendly cellulose acetate (CA) blended with glycerol (as an ionic liquid (IL)), mixed with polypyrrole (PPy, a conducting polymer) and doped with tungsten oxide (WO3) nanoparticles. The sensing membranes fabricated were used to detect H2S gas at room temperature and shown to exhibit high performance. The results revealed that the lowest operating temperature of both nanofiber and nanofilm sensors was 20oC, with a minimum gas detection limit of 1 ppm. Moreover, the sensor exhibits a reasonably fast response, with a minimum average response time of 22.8 and 31.7 s for the proposed nanofiber and nanofilm based sensors, respectively. Furthermore, the results obtained indicated an excellent reproducibility, long-term stability, and low humidity dependence. Such distinctive properties coupled with an easy fabrication technique provide a promising potential to achieve a precise monitoring of harmful H2S gas in both indoor and outdoor atmospheres

The co-existence of NAFLD and CHB is associated with suboptimal viral and biochemical response to CHB antiviral therapy: a systematic review and meta-analysis

Background and aimsChronic hepatitis B (CHB) and non-alcoholic fatty liver disease (NAFLD) are leading causes of liver-related morbidity and mortality. The interaction between these two disease processes is poorly defined and the impact of NAFLD on HBV-related cirrhosis and HCC remains unclear. The aim of this study was to evaluate the impact of NAFLD on response to antiviral CHB therapy to inform the debate on changing CHB treatment thresholds for these comorbid patients.MethodsStudies with a minimum of 50 adult CHB patients on nucleoside analogue therapy with or without concurrent NAFLD were identified from PubMed/Medline and EMBASE to February 21, 2023. Data extraction from each study included HBeAg and treatment status, diagnostic method of NAFLD, frequency of monitoring intervals, patient age, gender, grade of hepatic steatosis, BMI and metabolic comorbidities. The outcomes of interest, complete virological response (CVR), biochemical response (BR) and HBeAg loss/seroconversion, were recorded at each available monitoring interval. Comparing CHB-NAFLD and CHB-only groups, pooled odds ratios (OR) and 95% confidence intervals (CI) were calculated using random- or fixed-effects models depending on heterogeneity.ResultsFrom a search of 470 citations, we identified 32 potentially relevant papers. Overall, 11 studies, comprising 2580 unique patients, met the inclusion criteria of the meta-analysis. CHB-NAFLD patients exhibited significantly lower rates of CVR compared to CHB-only patients. This was demonstrated by an OR of 0.59 (0.38-0.93, p=0.001, I2 = 72%) at 12 months, which tapered off to an OR of 0.67 (0.48-0.95, p=0.02) at 60 months. CHB-NAFLD patients also exhibited significantly lower rates of BR compared to CHB-only patients, as demonstrated by ORs of 0.39 (0.24-0.62, p<0.0001, I2 = 53%) at 12 months and 0.33 (0.17-0.63, p=0.0008) at 24 months.ConclusionPatients with concurrent CHB and NAFLD experience delayed CVR to antiviral therapy and more persistent biochemical abnormalities in comparison to patients with CHB only. This supports the argument for earlier antiviral therapy in order to avert CHB complications in these multi-morbid patients, as the global disease burden of NAFLD continues to increase

Polarization-sensitive quantum-optical coherence tomography

We set forth a polarization-sensitive quantum-optical coherence tomography (PS-QOCT) technique that provides axial optical sectioning with polarization-sensitive capabilities. The technique provides a means for determining information about the optical path length between isotropic reflecting surfaces, the relative magnitude of the reflectance from each interface, the birefringence of the interstitial material, and the orientation of the optical axis of the sample. PS-QOCT is immune to sample dispersion and therefore permits measurements to be made at depths greater than those accessible via ordinary optical coherence tomography. We also provide a general Jones matrix theory for analyzing PS-QOCT systems and outline an experimental procedure for carrying out such measurements.Comment: 15 pages, 5 figures, to appear in Physical Review

Zwitterionic PEG-PC hydrogels modulate the foreign body response in a modulus-dependent manner

Reducing the foreign body response (FBR) to implanted biomaterials will enhance their performance in tissue engineering. Poly(ethylene glycol) (PEG) hydrogels are increasingly popular for this application due to their low cost, ease of use, and the ability to tune their compliance via molecular weight and crosslinking densities. PEG hydrogels can elicit chronic inflammation in vivo, but recent evidence has suggested that extremely hydrophilic, zwitterionic materials and particles can evade the immune system. To combine the advantages of PEG-based hydrogels with the hydrophilicity of zwitterions, we synthesized hydrogels with co-monomers PEG and the zwitterion phosphorylcholine (PC). Recent evidence suggests that stiff hydrogels elicit increased immune cell adhesion to hydrogels, which we attempted to reduce by increasing hydrogel hydrophilicity. Surprisingly, hydrogels with the highest amount of zwitterionic co-monomer elicited the highest FBR we observed. Lowering the hydrogel modulus (165 kPa to 3 kPa), or PC content (20 wt% to 0 wt%), mitigated this effect. A high density of macrophages was found at the surface of implants associated with a high FBR, and mass spectrometry analysis of the proteins adsorbed to these gels implicated extracellular matrix, immune response, and cell adhesion protein categories as drivers of macrophage recruitment to these hydrogels. Overall, we show that modulus regulates macrophage adhesion to zwitterionic-PEG hydrogels, and demonstrate that chemical modifications to hydrogels should be studied in parallel with their physical properties to optimize implant design

Influence of maturity stages on postharvest physico-chemical properties of grapefruit (Citrus paradisi var. ‘Shamber Tarnab’) under different storage durations

The present study was conducted to evaluate the effect of maturity stages on the physicochemical characteristics of grapefruit (Citrus paradisi cv. ‘Shamber Tarnab’) under storage conditions for 60 days at ambient temperature (16±1 °C with 55-60% relative humidity). Grapefruits were harvested at different maturity stages, namely mature green (MG) and full ripe (FR). The fruits of both stages were assessed for different physical quality parameters at 15 days interval. The experimental results showed that ascorbic acid content, titratable acidity, fruit firmness, percent disease incidence was higher at FR stage. In contrast, weight loss, percent juice content, total soluble solid (TSS), and TSS/acid ratio at MG (mature green) were lower than that of FR fruits. Regarding storage durations, the fruit firmness, titratable acidity, percent juice content, ascorbic acid content decreased significantly, whilst total soluble solid, TSS/Acid ratio, weight loss, and percent disease incidence increased significantly with the extension of storage duration from 0 to 60 days. As concerned to its interactive effects, the highest ascorbic acid content, titratable acidity, percent juice content, and maximum fruit firmness were observed in fresh grapefruit, harvested at (MG) mature green stages, whereas the maximum total soluble solid, percent disease incidence, and TSS/Acid ratio were recorded in fruit harvested at (FR) full ripe stage, stored for 60 days at room temperature. Similarly, the Pearson’s Correlation Analysis (p> 0.05) of grapefruit was positive effect for most of the quality traits of grapefruit at different storage durations and maturity stages. It was concluded that grapefruit could be harvested at the mature green stage (MG) for sustaining quality attributes up to 60 days of storage at room temperature

One-Way Entangled-Photon Autocompensating Quantum Cryptography

A new quantum cryptography implementation is presented that combines one-way operation with an autocompensating feature that has hitherto only been available in implementations that require the signal to make a round trip between the users. Using the concept of advanced waves, it is shown that this new implementation is related to the round-trip implementations in the same way that Ekert's two-particle scheme is related to the original one-particle scheme of Bennett and Brassard. The practical advantages and disadvantages of the proposed implementation are discussed in the context of existing schemes.Comment: 5 pages, 1 figure; Minor edits--conclusions unchanged; accepted for publication in Physical Review

Transcending the MAX phases concept of nanolaminated early transition metal carbides/nitrides -- the ZIA phases

A new potential class of nanolaminated and structurally complex materials, herein conceived as the Zigzag IntermetAllic (ZIA) phases, is proposed. A study of the constituent phases of a specific Nb--Si--Ni intermetallic alloy revealed that its ternary H-phase, \textit{i.e.}, the Nb$_3$SiNi$_2$ intermetallic compound (IMC), is a crystalline solid with the close-packed \textit{fcc} Bravais lattice, the 312 MAX phase stoichiometry and a layered atomic arrangement that may define an entire class of nanolaminated IMCs analogous to the nanolaminated ceramic compounds known today as the MAX phases. The electron microscopy investigation of the Nb$_{3}$SiNi$_{2}$ compound -- the first candidate ZIA phase -- revealed a remarkable structural complexity, as its ordered unit cell is made of 96 atoms. The ZIA phases extend the concept of nanolaminated crystalline solids well beyond the MAX phases family of early transition metal carbides/nitrides, most likely broadening the spectrum of achievable material properties into domains typically not covered by the MAX phases. Furthermore, this work uncovers that both families of nanolaminated crystalline solids, \textit{i.e.}, the herein introduced \textit{fcc} ZIA phases and all known variants of the \textit{hcp} MAX phases, obey the same overarching stoichiometric rule $P_{x+y}A_xN_y$, where $x$ and $y$ are integers ranging from 1 to 6