A Mini Review on Testing Methods for Mechanical Properties of Natural Fibre Honeycomb Sandwich Structure and Fractography Analysis

This paper is a review of the past research of mechanical testing methods for natural fibre honeycomb sandwich structure as well as failure modes analysis at a microscopic level by using Scanning Electron Microscope (SEM). As the world is garnering attention towards renewable resources for environmental purposes, studies of natural fibre have been increasing as well as the application of natural fibre throughout various industries such as aerospace, automobiles, and construction sectors. This paper is started with brief information regarding the honeycomb sandwich structure, introduction to natural fibre, its applications as well as the factors affecting the performances of the structure. Next, the mechanical testing methods are listed out as well as the expected outcomes obtained from the respective testing. The mechanical properties are also identified by conducting lab tests according to the ASTM standard for sandwich and core structures. The microstructure of the deformed samples is then examined under Scanning Electron Microscope (SEM) by using different magnifications to study the failure mechanisms of the samples. The images obtained from the SEM test are analyzed by using fractography which will show the failure modes of the samples. This article is based on past research conducted by professional on the related topic.

A graph theory model using human nature structure

A graph theory model of the human nature structure( GMH) for machine vision and image/graphics processing is described in this paper. Independent from the motion and deformation of contours,the human nature structure( HNS) embodies the most basic movement characteristics of the body. The human body can be divided into basic units like head,torso,and limbs. Using these basic units,a graph theory model for the HNS can be constructed. GMH provides a basic model for human posture processing,and the outline in the perspective projection plane is the body contour of an image. In addition,the GMH can be applied to articulated motion and deformable objects,e. g.,in the design and analysis of body posture,by modifying mapping parameters of the GMH.

The Land Use in Turkey: A General Assessment and Affecting Factors

Discussions related to land use in Turkey in recent years has been increasing. These discussions are mostly between those who want to protect the natural environment and those who demand other sectoral investment areas. However, there has not been a comprehensive and holistic study assessment of the land use, except for local studies. For this reason, the present study has been conducted in order to reveal the change in land use in the country’s geography. In order to achieve the aims of the study, the literature was reviewed, institutional data were compiled, and the results of previous local studies were evaluated using appropriate methods. Factors affecting land use were examined in the study and it was seen from the findings that significant land use changes occurred in the last 75 years. Although land use suitable for natural structure was common in advance, after the 1980s sectoral needs came to the fore. With the accelerated urbanization and industrialization, tourism, mining and dam areas have become widespread. It has been determined that there is a need for new scientific studies on land use, revision of ineffective laws, and national land use plans that take into account the sectoral needs in order to reduce the discussions.

Practical Engineering Behavior of Egyptian Collapsible Soils, Laboratory and <i>In-Situ</i>Experimental Study

In many sites on Egypt desert roads collapsible soils is broadly classified as a problematic soils containing silty fine sand which is cemented with low density and low degree of saturation which is susceptible to a large and sudden reduction in their volume upon inundation, with or without vibration in its stress. Four sites have been studied for new urban, roads and industry work sits, related to increase in natural water content. These soils go through radical rearrangement of their particles, causing sudden changes in the stress-deformation behavior which cause differential settlement of foundation and roads. This change in volume can lead to foundation failures and worth of damages under ground public facilities and infrastructure. In this study, the search program is developed to establish their different behavior under wetting in two phases: field and laboratory work. The obtained results are useful in mapping the trend of the factors affected in assessing soil collapsibility rate or collapse potentials which are observed in construction with volume change problems. The major factors observed are the natural structure skeleton of the soil particle and its grain size and mechanism of soil sedimentation. The field collapse potentials value assigned for these tested sites along Alexandria—Cairo desert road indicated that the field measured collapsibility potentials are smaller than those measured on the same extracted undisturbed samples in laboratory by 15%, which can be saved in coast, change in proposed collapsibility improvement method and change in select foundation type. Also, field tests evaluate the collapsibility rate with time and highlight that environmental history and natural soil structure in field are the important factors affected on these soil collapse, and also, knowledgeable by collapsible soils during wetting in these sites studied.

Energy-absorbing porous materials:Bioinspired architecture and fabrication

Energy-absorbing materials are widely used in transportations,sports,and the military applications.Particularly,porous materials,including natural and artificial materials,have attracted tremendous attentions due to their light weight and excellent energy absorption capability.This review summarizes the recent progresses in the natural and artificial energy-absorbing porous materials.First,we review the typical natural porous materials including cuttlebone,bighorn sheep horn,pomelo peel,and sunflower stem pith.The architectures,energy absorption abilities,and mechanisms of these typical natural materials and their bioinspired materials are summarized.Then,we provide a review on the fabrication methods of artificial energy-absorbing porous materials,such as conventional foaming and three-dimensional(3D)printing.Finally,we address the challenges and prospects for the future development of energy-absorbing porous materials.More importantly,our review provides a direct guidance for the design and fabrication of energy-absorbing porous materials required for various engineering applications.

Degradation of florfenicol in a flow-through electro-Fenton system enhanced by wood-derived block carbon(WBC)cathode

The flow-through electro-Fenton(EF-T)reactor with WBC cathode was designed to remove florfenicol(FF).The activated WBC cathode was prepared by facile carbonization and activation methods,and featured high specific surface area,natural multi-channel structure,abundant oxygen-containing groups,good hydrophilicity,and excellent O_(2)reducing capacity.WBC cathode was located above Ti/Ru-IrO_(2)mesh anode.O_(2)evolved at the anode was carried to the inner wall of channel of WBC by the force of buoyancy and water flow,which increases oxygen source of H_(2)O_(2)generation at the cathode.The flow-through system by using WBC electrode promote the mass transfer of O_(2)and FF.The production amount of H_(2)O_(2)at activated WBC was 32.2 mg/L,which was almost twice as much as that at non-activated WBC(15.0 mg/L).FF removal ratio in EF-T system was 98%,which was much higher than that of traditional flow-by electro-Fenton(EF-B,33%)or single electrooxidation system(EO,16%).EF-T system has the lowest energy consumption(4.367 kWh/kg)among the three electrochemical systems.The cathodic adsorption,anodic electrooxidation,and EF reaction are responsible for the degradation of FF.After five consecutive cycle experiments,FF removal ratio was still 98%,indicating WBC has the good stability.