Technological Properties of Improved Pigeon Pea Varieties in Machakos County, Kenya

Pigeon peas, a type of pulse, have immense nutritional potential to improve health in arid and semi-arid regions. However, unlocking this potential relies heavily on understanding their technological properties, such as hydration rate, volumetric expansion, and cooking time. These properties directly influence processing, accessibility, and acceptability as a food source. However, there is limited information on technological properties of improved varieties. The study aimed to determine technological properties of improved pigeon pea varieties grown in Machakos County. Seven improved pigeon peas varieties namely: KARI Mbaazi 1, KARI Mbaazi 2, ICEAP 00850, KAT 60/8, Mituki, Egerton Mbaazi 1, Egerton Mbaazi 2 and ICEAP 00554 (control variety) were used in this study. These varieties were tested for water absorption capacity (WAC), volumetric expansion, density, cooking time (CT) and total soluble solids (TSS) in the broth. The experiment was arranged in a Completely Randomized Design (CRD) replicated three times. Data analysis was conducted using SAS software version 9.1.3 (SAS, 2006). Means separation was done using Tukey’s honestly significant difference (HSD) at 95% Confidence Level. There were significant differences in water absorption capacity (WAC), volumetric expansion, density, TSS, and CT among the improved varieties (p p < 0.05). KARI Mbaazi 2 exhibited the greatest volumetric expansion after cooking (VEAC) at 11%. Additionally, control variety recorded the highest water absorption capacity (125.48%), which was significantly greater compared to the improved pigeon pea varieties. Cooking time in minutes was shortest for Mituki (46.0) and KAT 60/8 (55.7) and longest for both KARI Mbaazi 1 and ICEAP00850 at 160 minutes. All the varieties showed high TSS ranging from 10.5 to 26.7% indicating the potential to select varieties with desired flavour profiles. Improved pigeon pea varieties (Mituki and KAT60/8) displayed desired technological properties alongside the control variety. These findings inform the specific culinary applications and nutritional needs which enhance utilisation of pigeon peas as food. Further research is needed to determine the impact of the technological properties on the digestibility and glycaemic index of pigeon peas.

Physical-mechanical properties of microbially induced calcite precipitation-treated loess and treatment mechanism

Loess disintegration can lead to geotechnical engineering problems,e.g.,slope erosion,wetting-induced landslide,and hydroconsolidation.Microbially induced calcite precipitation(MICP)technique is a potential loess reinforcing method.This study investigated the physical-mechanical properties of MICP-treated loess and then explored the mechanism of loess modification by MICP.Here,loess first underwent MICP treatment,i.e.,mixing loess with Sporosarcina pasteurii and cementation solution(CS).Then,the effects of the CS concentration(0.2,0.6,0.8,and 1 M)on the physical and mechanical properties of the MICP-treated loess were tested.Finally,the static contact angle test,scanning electron microscopy(SEM),and X-ray diffractometry(XRD)were conducted to study the mechanism of MICP treatment on loess.Results showed the following property changes of loess after MICP treatment:the liquid limit decreased by 1.7%,the average particle size increased from 6 to 47μm,the specific gravity decreased from 2.65 to 2.43,the unconfined compressive strength increased from 37 to 71 k Pa,and the disintegration time increased from 10 to 25 min.Besides,the shear strength also increased,and the shear strength parameters(cohesion c and internal friction angle?)varied with the CS concentration.The static contact angle tests indicated that the water absorption ability of loess was reduced after MICP treatment.SEM and XRD results verified that the CaCO_(3)from MICP was attributed to the above results.The above findings explained the mechanism of MICP treatment of loess:the CaCO_(3)coats and cements the particles,and fills the pores of loess,improving the strength and water stability of loess.

Comparison and analysis of the main technological factors of influencing mechanical properties of scrimber and PSL

The main mechanical properties of scrimber and Parallel Strand Lumber (PSL) were researched through techno-logical test. Experimental materials of scrimber are small log of Aspen, Dahurian larch and Birch. Experimental materials of PSL come from fishtail veneer strips at plywood plant of Aspen and Birch. In the laboratory conditions low quality small log and wood residues can yield scrimber and PSL with high strength. After the technological conditions of scrimber were compared with that of PSL, the main factors of influencing their properties were separately pointed out and the reasons influencing proper-ties have been analyzed in this paper. The results showed that the hot-pressing pressure is an important technological factor for scrimber. The ratio of veneer-strand length to thickness is a key technological factor for PSL.

The difference analysis of physical-mechanical properties of sediments in the central South Yellow Sea and Zhe-Min coastal area in China

The difference analysis of physical-mechanical properties of muddy sediments is made in the central South Yellow Sea and the Zhe-Min（Zhejiang Province to Fujian Province of China） coastal area. The results show that sediments in the two regions are both dominated by mud. There are perfect negative power function correlations between the water content and the density, the compression coefficient and the compression modulus; a good positive power function correlation between the liquid limit and the plastic limit, a perfect positive linear correlation between the water content and the void ratio, and a perfect polynomial function correlation between the miniature vane shear strength and the pocket penetration resistance. In general, compared with sediments in the Zhe-Min coastal area, sediments in the central South Yellow Sea possess high water content, high void ratio,low density, high plasticity, high compressibility, low shear strength. The causes of the differences between physical-mechanical properties of sediments are analyzed from the topographic features, material sources,hydrodynamic conditions, deposition rate, and material composition. Compared with the Zhe-Min coastal area,the central South Yellow Sea is far from the Mainland and low-lying; has poor hydrodynamic condition; the materials diffused to the area are less and dominated by fine clay, have the high content of smectite and organic matters. These factors lead to sediments of the central South Yellow Sea has the higher water content, the higher plasticity, the lower density, and the lower strength than sediments in the Zhe-Min coastal area.

Effect of Hot Processing Technology on Mechanical Properties and Structure of Interface of Ti/Steel Composite Sheet

研究了热加工工艺对钛-钢复合板界面力学性能和显微组织的影响。测试了在A，B，C，D4种温度下热轧复合板界面的力学性能，用金相显微镜及扫描电镜观察了界面显微组织并分析了界面的成分。结果表明，在A，B2种温度下轧制的钛-钢复合板界面机械性能良好，延伸率高，其剪切强度不但可保持坯料原有的水平，甚至还略有增加。在C，D2种温度下轧制的钛-钢复合板界面机械性能相对较低，延伸率较高，但剪切强度要比爆炸复合坯料低，尤其是D加热温度，轧制后界面剪切强度急剧下降。热轧的终轧温度也是影响钛-钢复合板界面结合性能的重要因素。在低于相转变温度的合适温区热轧，且终轧温度合适，获得的钛-钢复合板结合界面无爆炸波纹，没有污染，生产的脆性化合物极细小，组织类同于钛材完全退火的等轴组织。

Effects of Processing Technologies on Mechanical Properties of SiC Particulate Reinforced Magnesium Matrix Composites

Mg matrix composites with SiC particles ranging from 5vol%-25vol% were prepared using stirring casting method. Die casting, squeezing casting, and extrusion were applied for inhibiting or eliminating the defects such as gas porosity and shrinkage void. Through die casting and squeezing casting, most of the defects in Mg matrix composites could be eliminated, but the mechanical properties were improved limitedly. On the other hand, after hot extrusion, not only most of the defects of as-cast composites ingots were eliminated, but also the mechanical properties were improved markedly. With the addition of SiC, the tensile strength, yield strength and elastic modulus of as extrusion SiCp/AZ61 composites increased remarkably, and the elongation decreased obviously.

The study of measuring technology on the dynamic mechanical properties of welded joint with high strainrate

In this paper, to meet the needs of studying work of dynamic mechanical properties of welded joint, the dynamic mechanical properties of welded joint were measured by means of SHPB(Split Hopkinson Pressure Bar).The dynamic mechanical property's curves of every part of welded joint were obtained. For studying the dynamic behavior of mechanical heterogeneity of welded joint, important data were offered. The method of test creates a new way of studying dynamic mechanical properties of welded joint.

Effects of High-Pressure Technology on the Functional Properties of Milk and Fermented Milk Products

HPP （high pressure processing） is one of the novel technologies to produce microbiologically safe food. HPP is a non-thermal food processing method, wherein the food is subjected to a very high pressure ranging between 100-800 MPa in order to prevent undesirable chemical and microbiological reactions, and hence, prolong the shelf-life. HPP is also called as ＂high hydrostatic processing, ultra-high pressure processing or isostatic processing＂. In dairy products, HHP has the potential to modify the functional properties of proteins, polysaccharides and alter biochemical reactions without significantly affecting the nutritional and sensory properties. HPP treatment induces significant changes in milk components particularly in proteins （whey proteins and caseins）, as well as on their applicability in innovative dairy productions. HPP influences technological properties of various milk products such as firmness, water-holding capacity of the gel and network structure, cheese yield, rennet coagulation time and ripening.

Effect of Rare Earths on Microstructure and Properties of Sn2.0Ag0.7CuRE Solder Alloy for Surface Mount Technology

A new type of lead-free solder alloy Sn2.0Ag0.7CuRE was fabricated under vacuum condition. The microstructure and properties of the material, such as tensile strength, elongation, melting range, conductance and spreading area were all investigated. Result shows that when the content of RE ≤ 0.1% （mass fraction）, RE distribute uniformly in the solder alloy, and the tensile strength and conductance of Sn2.0Ag0.7CuRE solder alloy are better than those of traditional Sn37Pb solder. Its elongation and spreading area are almost equal to those of Sn37Pb solder. When the content of RE reaches 0.5%, RE compounds can be easily found around the boundaries of grains and phases, and the tensile strength and elongation and spreading area of Sn2.0Ag0.7CuRE solder alloy all decrease sharply. Therefore, RE amount added to the Sn2.0Ag0.7CuRE solder alloy under 0.1% is proper.

Study of Manufacturing Technology and Properties of AVGCI with Rare Earths

By vermicularizing agent containing RE (REFeSi), austempered vermicular graphite cast iron (AVGCI) with RE can be produced with austempered treatment. The process of austenitization of vermicular graphite cast iron (VGCI) with RE and the transformation of AVGCI with RE with temperature increasing were studied by SEM with heating device. Properties of AVGCI with RE, such as tensile strength, elongation, impact toughness, hardness, thermal fatigue resistance, thermal expansive coefficient and weight increasing by oxidation were measured by electron universal testing machine with heating device. Experimental results indicate that AVGCI with RE possesses good comprehensive properties at room and elevated temperatures.

Effect of pressure on the electrical properties of flexible NiPc thin films fabricated by rubbing-in technology

Nickel phthalocyanine(Ni Pc) film was deposited onto the surface of flexible conductive glass by rubbing-in technology and used to fabricate devices based on ITO/Ni Pc/CNT/rubber structure. The I–V characteristics of the devices were investigated under different uniaxial pressures of 200, 280, and 480 gf/cm^(2), applied perpendicular to the surface of the Ni Pc film. Results showed that the nonlinearity coefficients of the I–V curves are in the range of 2 to 3, which was found to be decreased with the increase of the pressure. The rectification ratio of the devices was estimated to be varied from 1.5 to 3 based on the applied pressure. Concluding, the resistance of the active layers was decreased with the increase of both pressure and voltage. We believe that using the rubbing-in technology under sufficient applied pressure it is possible to utilize Ni Pc for the development of various electronic devices such as diodes, nonlinear resistors, and sensors.

INVESTIGATION ON MECHANICAL PROPERTIES OF ZN-AL/SIC PARTICULATE COMPOSITES

In order to improve the properties of ZA 27 and ZA4-3 zinc alloys and broaden their application ranges,SiC particlj1Ale composites, prepared by means of rheological casting technology, are investigated individually on their rT..t'llanical properties. The results of ne-cural strength, impact strensttl, compressive strength, hardness values and wear rate of the composites show that the addition of SiCp, leads to the increase of the compressive strength and hardness values at both room and higher temperature, and wear resistance of the materials, accompanying with the slight decrease of the fie-cural strength and sharp reduction of the impacttoughness. The factors affecting the mechanical properties of the composites are discussed in the paper.

Construction and Properties of Structure-and Size-controlled Micro/Nano-energetic Materials

The recent research progress of structure- and size-controlled micro/nano-energetic materials is reviewed, which properties are fundamentally different from those of their corresponding bulk materials. The development of the construction strategies for achieving zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) micro/nanostructures from energetic molecules is introduced. Also, an overview of the unique properties induced by micro/nanostructures and size effects is provided. Special emphasis is focused on the size-dependent properties that are different from those of the conventional micro-sized energetic materials, such as thermal decomposition, sensitivity, combustion and detonation, and compaction behaviors. A conclusion and our view of the future development of micro/nano-energetic materials and devices are given.

Effect of ultrasonic irradiation on rheological properties of asphaltenic crude oils

In this work, the rheological changes of several crude oil samples exposed to ultrasonic waves for different time intervals in addition to the effect of temperature on viscosity behavior of heavy crude oils were investigated using a series of steady shear flow and oscillatory tests. The colloidal structural evolutions of flocs in oil samples were illustrated by analysis of the size distribution of flocculated asphaltene particles （confocal microscopy tests）. The rheological investigations indicate that the ultrasonic irradiation dissolved heavy components in crude oil. After ultrasonic treatment, the Kouh-e-Mond crude oil was found to be pseudoplastic. In addition, confocal microscopy confirms that there was an optimum duration for ultrasonic irradiation, at which the viscosity and flocculation rate of asphaltenic crude oils reduced to the minimum values. The optimum was found to be approximately 40 min for the Kouh-e-Mond crude oil. Experimental results illustrate that the ultrasonic irradiation could disaggregate heavy colloid components in crude oil, and breakdown of asphaltene molecules would only occur in a specific time interval of irradiation. Also according to the temperature sweep test, the oil temperature rise caused by ultrasonic irradiation was not the main reason for theological changes of the crude oil and this alteration may be due to physical and chemical phenomena induced by sonication in crude oil.

Sintering behavior, microstructure and properties of TiC-FeCr hard alloy

TiC based cermets were produced with FeCr, as a binder, by conventional P/M （powder metallurgy） to near 〉97% of the theoretical density. Sintering temperature significantly affects the mechanical properties of the composite. The sintering temperature of 〉1360℃ caused severe chemical reaction between TiC particles and the binder phase. In the TiC-FeCr cermets, the mechanical properties did not vary linearly with the carbide content. Optimum mechanical properties were found in the composite containing 57wt% TiC reinforcement, when sintered at 1360℃ for 1 h. Use of carbon as an additive enhanced the mechanical properties of the composites. Cermets containing carbon as an additive with 49wt% TiC exhibited attractive mechanical properties. The microstructure of the developed composite contained less or no debonding, representing good wettabifity of the binder with TiC particles. Homogeneous distribution of the TiC particles ensured the presence of isotropic mechanical properties and homogeneous distribution of stresses in the composite. Preliminary experiments for evaluation of the oxidation resistance of FeCr bonded TiC cermets indicate that they are more resistant than WC-Co hardmetals.

Mechanical properties and damage characteristics of solidified body-coal combination in continuous driving and gangue backfilling

Recovery of the coal buried under buildings,railways and water bodies and the residual coal in irregularly arranged fully mechanized mining faces is a common engineering problem facing underground coal mining.In this study,a mining technology of continuous driving and gangue backfilling(CDGB)was proposed.The technology,which can not only alleviate ground subsidence and gangue discharge,but also release the above-mentioned coals,contributes to green and efficient sustainable development of mining.The stability of the system of the solidified body-reserved coal pillar combination(S-C combination)is crucial to the CDGB technology.Therefore,it is of great significance to explore the mechanical and damage characteristics of S-C combination in the synergistic bearing process.First,four sets of differentshaped S-C combination specimens were fabricated and a S-C combination bearing structure in CDGB was constructed to explore the differences in mechanical characteristics and damage modes of different-shaped S-C combination specimens during CDGB.Subsequently,their surface strain field evolutions and acoustic emission(AE)response characteristics in the load-bearing process were obtained with the aid of the digital image correlation technique and the AE signal monitoring system.Furthermore,a damage evolution model based on AE parameters and mechanical parameters was established to clarify the damage evolution law.The following results were obtained:(1)The free area of S-C combination can serve as a quantitative index to evaluate the stability of the overburden control system;(2)The concept of critical value k of the free area was first proposed.When the free area exceeds the critical value k(free area ratio greater than 1.13),the deformation resistance and the free area changes becomes negatively correlated;(3)As the free area expands,the failure of the S-C combination specimen evolves from tensile failure to shear failure.The distribution characteristics of the axial strain field also verified such a change in the failure mode;(4)When the free area expands,the peak AE count gradually changes from“double peaks”to“a single peak”.In this process,the expansion of free area shortens the time for accumulating and releasing energy during loading.Micro cracks generated in the specimen change from a phased steep growth to a continuous increase,and the process in which micro cracks develop,converge,intersect and connect to form macro cracks accelerates.The damage evolution law concluded based on AE parameters and mechanical parameters can well characterize the damage evolution process of S-C combination,providing certain reference for the study on the synergistic bearing of S-C combination during CDGB.

Study of corneal biomechanical properties in patients with childhood glaucoma

AIM:To study of corneal biomechanical properties and intraocular pressure(IOP)measured with Corvis Scheimpflug Technology(ST)in patients with childhood glaucoma(CG).METHODS:Cross-sectional study in which 89 eyes were included 56 of them with CG.Only one eye per patient was included.The following variables were obtained from the clinical history and the ophthalmological examination:age,sex,IOP,number of surgeries,and the cup/disc ratio(CDR).The following parameters were recorded using Corvis ST:corrected by biomechanics IOP(b IOP),not corrected IOP(nct IOP),central corneal thickness(CCT),maximum concavity[radius,peak distance(PD)and deformation amplitude],applanation 1 and 2(length and velocity).The mean age was 23±14.55 and 33±19.5 years old for the control group and CG group,respectively.Totally 36 were males and 53 were females.In the CG group,7 patients were controlled only with medical treatment.Sixteen had at least one previous goniotomy,19 had at least one trabeculectomy,and 11 had an Ahmed implant.RESULTS:A significant and positive intraclass correlation coefficient was found between Goldman IOP and the IOP measured by Corvis in both groups.No differences were found between the IOP measured with Corvis and Goldman using a student t-test.Regarding biomechanical parameters,there were differences in the applanation length 2(A-L2),in the applanation velocity 2(A-V2)and in the PD.By sex,only the applanation length 1(A-L1)was found to be different in control group.A positive and significant Pearson correlation was found between CDR and the A-L1.CONCLUSION:Corneal biomechanical properties have shown differences between CG and healthy subjects and also between men and women.

Study of microstructures and properties for girth weldingof domestic X70 pipeline steels

With the development of domestic pipeline steels, it is necessary to develop suitable welding technology which can improve the properties of the welded pipeline. In this paper, the microstructures and mechanical properties of domestic XTO pipeline steels and welded joints are discussed. The welding consumables of BOHLER E6010 and HOBART 81N1 are matched for girth welding. The following characteristics in heat-affected zone（ HAZ） are indicated that microstructures of intercritical HAZ（ ICHAZ） is finer and more uniform, the grain sizes of fine-grain HAZ （ FGHAZ） and subcritical HAZ （ SCHAZ） are smaller than that of coarse-grain HAZ（ CGHAZ）. The hardness, tensile strength and toughness of welded joints come up to the standard. The micrographs of impact specimens in welded joints are cleavage, quasi-cleavage and dimple which shows there is typical ductile rupture.

Mechanical Behaviors and Deformation Properties of Retaining Wall Formed by Grouting Mould-Bag Pile

The simplified mechanical model and finite element model are established on the basis of the measured results and analysis of the grouting pile deformation monitoring,surface horizontal displacement and vertical displacement monitoring,deep horizontal displacement(inclinometer)monitoring,soil pressure monitoring and seepage pressure monitoring in the lower reaches of Wuan River regulation project in Shishi,Fujian Province.The mechanical behavior and deformation performance of mould-bag pile retaining wall formed after controlled cement grouting in the silty stratum of the test section are analyzed and compared.The results show that the use of controlled cement grouting mould-bag pile technology is to strengthen the soft stratum for sealing water and reinforcement,so that it can rock into a retaining wall,which can both retain soil and seal water with excellent effect.The control of cement grouting technology not only makes the soft soil rock in the range of retaining wall of mould-bag pile,but also makes a wide range of soil around the mould-bag pile squeeze and embed to compaction;and its cohesion and internal friction angle increased,so as to achieve the purpose of reducing soil pressure and improving mechanical and deformation properties of retaining wall.