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In the present study, a new type of radiation shielding material was developed by using a 3-D printing technique which enables to create a light radiation shielding materials of a great variety of shapes and dimensions. Micro and nano bismuth particles were incorporated as a filler between the inner layers of polylactic acid thermoplastic polymer (PLA Plastic) designed of the investigated 3-D printed prototypes to achieve the desired radiation attenuation. The effect of particle size on the attenuation parameters were studied over the energy range from 0.0595 to 1.41 MeV. The mass and thickness needed to reduce the intensity of the incoming radiation to half of its original value were determined experimentally for pure polymer (ABS Plastic), polymer with bulk Bi, and polymer with nano Bi. The results reveal that bismuth NPs with average particle size of about 17 ± 3 nm have a greater mass attenuation capability than normal bulk bismuth particles, meaning they are more efficient and a lighter shield can be produced. The enhanced shielding ability of nano bismuth particles was contributed to the excellent particle distribution, leading to an increase in the probability of photons interacting with the bismuth atoms. The bismuth NPs 3-D printed objects can be considered as a promising radiation shielding candidates and also could be utilized in manufacturing of radiation medical phantom.

A newly proposed p-Laplacian nonperiodic boundary value problem is studied in this research paper in the form of generalized Caputo fractional derivatives. The existence and uniqueness of solutions are fully investigated for this problem using some fixed point theorems such as Banach and Schauder. This work is supported with an example to apply all obtained new results and validate their applicability.

This work investigates the existence and uniqueness of solutions for a coupled system of fractional differential equations with three-point generalized fractional integral boundary conditions within generalized proportional fractional derivatives of the Riemann-Liouville type. By using the Schauder and Banach fixed point theorems, we study the existence and uniqueness of solutions for the aforesaid system. Finally, we present an example to validate our theoretical outcomes.

The full-energy peak efficiency of high-purity germanium well-type detector is extremely important to calculate the absolute activities of natural and artificial radionuclides for samples with low radioactivity. In this work, the efficiency transfer method in an integral form is proposed to calculate the full-energy peak efficiency and to correct the coincidence summing effect for a high-purity germanium well-type detector. This technique is based on the calculation of the ratio of the effective solid angles subtended by the well-type detector with cylindrical sources measured inside detector cavity and an axial point source measured out the detector cavity including the attenuation of the photon by the absorber system. This technique can be easily applied in establishing the efficiency calibration curves of well-type detectors. The calculated values of the efficiency are in good agreement with the experimental calibration data obtained with a mixed γ -ray standard source containing 60 Co and 88 Y.

We investigate the existence of solutions for a nonlinear fractional differential inclusion in a sense of hybrid Caputo-proportional fractional derivatives (HCPFDs) in Banach spaces. The main result is discussed by using the set-valued concern from the Mönch fixed-point theorem along with the Kuratowski measure of noncompactness. We present an example to demonstrate theoretical findings.

In this work, some marble types were collected from Egypt, and their shielding characteristics were estimated. Their rigidity, in addition to their elegant shape, led us to consider their use as a protective shield, in addition to making the workplace more beautiful. The mass attenuation coefficient (μ/ρ) was calculated for three types of marble (Breshia, Galala, and Trista) experimentally, using a narrow gamma ray source and high pure germanium (HPGe). The results obtained were compared with the XCOM program and indicated a very good agreement between the two methods. The linear attenuation coefficient (μ) was evaluated to calculate the half and tenth value layers. The maximum μ value of 1.055, 1.041, and 1.024 cm−1 was obtained for Breshia, Galala, and Trista, respectively, at 0.06 MeV. The mean free path for studying the materials was compared with other shielding materials and showed good results at different energy scales. The energy absorption (EABF) and exposure buildup factors (EBF) were determined at different mean free paths. The fast neutron removal cross section ΣR was calculated and expresses the ability of the marbles to slow down fast neutrons through multiple scattering. This is the ability of the marbles to shield fast neutrons.

Polyhydroxyalkanoates (PHAs) are biodegradable polymer biosynthesized via bacterial fermentation of sugars and fatty acids. PHA are considered a promising material to aid in mitigating plastic pollution due to their biodegradability. However, major bottleneck in the commercial feasibility of PHA production is the cost of PHA which remains a distinct challenge in the upscale production substituting the petroleum-based synthetic plastics for wider usage. The discharge of wastes and by-products of agricultural and industrial origins has created severe environmental pollution. Hence, waste utilization as carbon sources in the production of polyhydroxyalkanoates (PHA) would reduce the production costs, lessen waste and reduce pollution. This review provides an overview of utilisation of wastes and by-products for PHA production and the possibility of large-scale production. Potential drawbacks and opportunities are discussed in this review in integrating the sustainable production of PHAs into the global circular economy. This can pave the way in embracing low carbon bioeconomy. Graphical abstract

In this study, eight cases of workers in gamma camera scans and Positron Emission Tomography (PET/CT scan) fields (employed for various medical diagnoses) had their complete blood counts (CBCs) assessed. From the first hour of work until the last, the investigation of radiation’s impact on hematology was ongoing. By using a personal dose meter (Geiger Badge), the radiation exposure reading for a whole workday is directly recorded in (μSv). The study concluded that while the number of WBC count increased for all workers after radiation exposure, the number of RBC count decreased after exposure, suggesting that RBC amount may be a reliable indicator of exposure degree.

Background Periprosthetic infection following total knee arthroplasty is a devastating complication, which is not always satisfactorily resolved by revision surgery. Arthrodesis is a salvage alternative to above-knee amputation or permanent resection arthroplasty. Fixation options include internal compression plating, external fixation, and intramedullary nails. Methods We retrospectively reviewed twelve consecutive cases (9 males, 3 females; mean age, 67 years) of knee arthrodesis with a long intramedullary nail, performed at a single institution between 2003 and 2014. Desired outcomes were the ability to mobilize without pain, solid radiographic fusion, and the eradication of infection. Results Mean follow-up was 48.5 months (range, 9–120 months). Eleven patients (92 %) demonstrated stable fusion, ten patients (83 %) were ambulatory without pain, and ten patients (83 %) remained without infection at most recent follow-up. Eight patients (67 %) achieved union at an average of 12 months; three required repeat procedures, achieving union at an average of 9 months. There was a significant difference ( P  < 0.01) between the numbers of previous operations amongst the eight patients who initially achieved union (mean, 3.25) and three who subsequently required repeat procedures (mean, 8.33). Conclusions In contrast to similar studies, we performed a single-stage exchange where possible, while comparable ambulatory and fusion rates were observed. Numerous previous attempts at revision arthroplasty, co-morbidities, and infections with highly resistant organisms have been associated with further complications. Although technically challenging, knee arthrodesis with a long intramedullary nail offers an acceptable limb salvage procedure for carefully selected patients with complex periprosthetic infections.

Transaction costs are costs that appear in almost every economic transaction. The existence of transaction costs creates production cost inefficiencies. This research aims to identify the production costs borne by rose farmers as one of the leading commodities in East Java, especially Batu City. Apart from that, this research also identifies transaction costs that make production costs inefficient. The method used in this study is qualitative. The data collection tool used was unstructured interviews with rose farmer group administrators in Gunungsari Village, Batu City. Based on the research results, without transaction costs, the average total costs incurred by rose farmers in cutting rose farming is IDR 43,565,085.78 per planting season. The research results also show that there are six types of transaction costs that we have identified. These costs consist of explicit and implicit costs. Explicit costs refer to costs that are clear in amount and farmers know the exact data. Meanwhile, implicit costs refer to costs that farmers do not know the exact amount of.