Theoretical Study for the Calculation of Proton Range in Human Body Tissues

The main rationale for using charged particles in radiation therapy is the strong rise of energy loss (deposited dose) with maximum penetration depth ( Bragg peak) and rapid dose deposited behind the peak. Thus, a large dose can be applied to a deep seated tumor, with saving the surrounding normal tissues . Proton radiotherapy is nowadays an established method in the management of cancer diseases, although its availability is still limited to a few specialized centers. In this study, the range and the stopping power for proton interaction in the skeleton and intestine tissues, for an energy range from 0.01 to 300 MeV, was studied. The numerical calculations and analyses of Bethe Ziegler, along with CASP and SRIM software programs, were applied using Matlab program. The absorbed dose and the Bragg peak were calculated and presented as tables and figures .

Modelling of diesel fuel penetration depth in protective sand bed

When deploying a temporary fuel storage warehouse, the primary source of soil contamination by oil products is technological losses related to the leakage of isolation valves. To protect the soil from contamination, containers are placed on a layer of sand. The thickness of the sand layer depends on the volume of possible losses. The purpose of the work is to model the depth of diesel fuel penetration into the protective layer of sand bed. The method of performing the experiment imitated a high rate of fuel penetration in the form of droplets onto the protective layer. The article considers the mechanism of fuel penetration into sand and factors, determining the penetration depth. It is established that the mechanism of fuel penetration into the protective layer has two stages, on each of which the penetration depth and rate of fuel distribution are different. The maximum penetration depth is reached on the first stage and depends on the quantity of fuel. The author developed the model, which allows the determination of the thickness of the sand bed protective layer with known granulometric particle composition necessary for the prevention of diesel fuel penetration into soil.

A Nanoindentation Study on Al (TiFe-Mg-SiC) Composites Fabricated via Stir Casting

The limitations of aluminium in most engineering applications has led to the development of aluminium matrix composites with improved microstructural and mechanical properties. Nanoindentation techniques was used in assessing the mechanical properties of fabricated aluminium matrix composites with ferrotitanium and silicon carbide as reinforcements. Results from nanoindentation experiments shows the dependence of modulus of elasticity, microhardness and contact depth on the dispersion of ferrotitanium and silicon carbide reinforcements within the aluminium matrix. Highest nanohardness value was observed in composite with 7 wt. % silicon carbide, while the lowest elastic modulus was recorded in as-cast aluminium. Further analysis of specimens confirmed a decrease in maximum penetration depth with respective increase in the addition of silicon carbide reinforcements in the fabricated composites.

Estimation of Vs Structure of Krueng Aceh and its Suburb Basin of Aceh Province, Indonesia, Derived from Microtremor Measurements

The Aceh and Seulimeum Faults flank the Krueng Aceh Basin in Indonesia, and the shear-wave velocity (Vs) structure of the basin is not extensively available. Understanding the Vs structure is very important in order to figure out how the basin structures seemingly appear, and this can eventually be used to generate a microzonation map for other forthcoming studies. To provide this, Vs was measured over an area approximately covering Banda Aceh City and its surroundings, by setting two lines consisting of eight points projected in the NW–SE and SW–NE orientations. This research aims to facilitate the approximation of the Vs structure characteristics of the Krueng Aceh Basin using the microtremor array method (MAM). Triangular configurations were set by deploying four seismometers following an M-station geometry for three different array sizes (i.e., 3, 10, and 30 m in distance). The data were then processed by utilizing the spatial autocorrelation (SPAC) technique. The result shows that the Vs structure generally dips down from SE to NW, and it gradually declines from SW to NE. The combination of these Vs structures tends to be oblique toward the SW–NE direction. This form may be affected by the Aceh Segment Fault which is more active than the Seulimeum Segment Fault. The average maximum penetration depth and Vs are 603 m and 947.5 m/s in the SE–NW orientation, and 650 m and 958 m/s in the SW–NE direction. Generally, the thickness of the strata is greater in the upstream area compared to the downstream area. Their composition consists of alluvium (A) at the uppermost layer and diluvium (D) at the underlying layers. Then, all of the identified strata are aged from the Pleistocene to Tertiary Pleistocene (Tp). These characteristics of the strata could potentially cause surface damages as a result of site effect responses when an earthquake is occurring.

Design and Tests of a Multi-pin Flexible Seedling Pick-up Gripper for Automatic Transplanting

HighlightsA multi-pin flexible pick-up gripper with a four-jaw chuck having four pick-up pins has been developed.The gripper can effectively grasp, hold and release plug seedlings with low damages to the plants and the root soil.Based on a typical on-off control and cylinder stroke position detection, the control system for timely response was designed to automate the process of picking up and releasing seedlings.Abstract. A multi-pin flexible seedling pick-up gripper for automatic transplanting was developed and evaluated. The gripper having a four-jaw chuck mainly consists of a parallel-type air gripper with four fingers, four fork frames, four cylinder fingers, and several connecting/supporting parts. The air gripper moves to open and close the cylinder fingers, and the cylinder fingers each having a flexible pin grasp and release the seedling. When the pick-up gripper extracts seedlings from the tray cells, its four cylindrical fingers push out four pick-up pins to penetrate deep into the root soil and then close, making the pick-up pins to firmly hold the root soil for lifting. When the pick-up gripper releases seedlings, its fingers open, making the pick-up pins loosen the root soil and then pull back for discharging. An electrical and pneumatic control system was designed to coordinate the execution of each action. The pick-up gripper attached to a robotic manipulator was tested on a range of plug seedling transplanting parameters and conditions. The results showed that penetration depth, seedling species, and the interaction of working pressure and seedling species significantly influenced the successful automatic transplanting. On the whole, the seedling integrity ratio in automatic transplanting was found to be up to 93.37%. For optimum performance of the device in transplanting seedlings, the pick-up pins of the multi-pin gripper need to grasp the maximum amount of root soil at their maximum penetration depth. Keywords: Gripper, Flexible, Multi-pin, Seedlings, Transplanting.

The New Swedish Cyprus Expedition 2017: Excavations at Hala Sultan Tekke (The Söderberg Expedition). Preliminary results

During the eighth field season at the Bronze Age city of Hala Sultan Tekke, excavations in City Quarter 1 (CQ1) exposed massive industrial and domestic structures belonging to three phases of occupation (Strata 3–1) dating to the 13th and 12th centuries BC (LC IIC–IIIA). Georadar survey, penetrating to a maximum depth of approximately 1 m, guided the excavation of walls of Strata 1–2, both of which were destroyed by conflagration. Excavations 1.5–2 m below the surface and also below the maximum penetration depth of the radar revealed a heretofore buried phase of occupation with substantial architectural units. For the first time, massive Stratum 3 structures with a markedly different building technique were exposed. Copper smelting installations, much ash and slag, and storage facilities also belong to this phase of occupation. Additional excavations guided by results from a magnetometer survey were carried out in Area A, roughly 600 m to the south-east of CQ1. Numerous circular anomalies were excavated. These were identified as Late Cypriot wells, rich offering pits, and a tomb from the same period. In addition to numerous intact locally produced vessels and other finds, the tomb contained a complete Late Minoan II/IIIA piriform jar with bird motifs which have exact parallels from Knossos. Other finds from this tomb include a diadem of leaf gold, amethyst jewellery, and nine sphendonoid shaped balance weights of haematite together with a hornblende whetstone. The features from Area A cover a period from the 16th to the 13th centuries BC (LC IB–IIC).

Stress, Hardness and Elastic Modulus of Bismuth Triiodide (BiI3)

ABSTRACTBismuth triiodide (BiI3) has been studied aiming the development of lead-free photovoltaic materials. It can also be used as X-ray detectors due to the high density of its elements (bismuth and iodine). We investigate the mechanical stress, hardness, and elastic properties of BiI3 thin films deposited by thermal evaporation. The stress was determined by the bending beam technique using the Stoney equation. The films are tensile with stress of approximately 27 MPa. The hardness and the elastic modulus were determined by nanoindentation technique using a Berkovich diamond tip. The hardness of the films is approximately 0.8 GPa and the reduced Young´s modulus is ∼28 GPa for maximum penetration depth of 10% of the film thickness.

A Comparative Study on the Cyclic Behavior of Austenite/Ferrite Phases Characterized by the Nanoindentation

The cyclic deformation behavior of the austenite and ferrite phase in an austenite-ferrite duplex stainless steel was studied by using the load-controlled cyclic nanoindentation approach. The results showed that the maximum penetration depth onto both austenite and ferrite phases increased continuously while the rate decreased gradually and finally reached to a constant during the repeated indentation. Both transient state and quasi-steady state were observed for the penetration depth per cycle on both of the austenite and ferrite phases with the increased cycles. By contrast, both the penetration depth and rate per cycle into the austenite phase were larger than those into the ferrite phase. This was ascribed to the stress-induced densification in the austenite and ferrite phases and strain-induced transformed martensite in the austenite phase.