Techno-economic analysis and a novel assessment technique of paper mill sludge conversion to bioethanol toward sustainable energy production

A novel bioprocess design to convert paper mill sludge (PMS) to biofuels is proposed in this work. The design utilizes cellulosic fiber recovered from the PMS via optimized de-ashing (HCl washing) step. This work specifically provided a technical and economic analysis of paper mill sludge conversion into biofuel production using a novel protocol. The protocol is based on scanning electron microscopy (SEM) analysis to assess the quality of the contained cellulose prior to further processing. The results are crucially important to determine the suitability of the PMS feedstock to produce biofuels. SEM analysis was employed as a preliminary screening tool to evaluate sludge digestibility and conversion. The SEM characterization technique established a direct relationship between the fiber morphology, presence of crystals salts and sugar yield after enzymatic hydrolysis. Substantial structural changes were observed before and after de-ashing the sludge samples, leading to a correlation between the surface morphology and the washing step. The results suggested that de-ashing changes the surface morphology and upon analysis, increased the sugar yield up to about 86% as opposed to 2.2% in sludge sample A as an example. The PMS conversion into biofuel was simulated using Aspen PLUS and compared to a similar process using corn stover as feedstock. The simulation results showed it is 20% cheaper to produce bioethanol from PMS compared to corn stover. The simulation revealed less energy demand by around 13 320 MJ/h compared to that when corn stover was used.     

Optimum stacking sequence design of composite laminates for maximum buckling load capacity using parameter-less optimization algorithms

This paper presents a comparative study of the application of parameter-less meta-heuristic algorithms in optimum stacking sequence design of com of composite laminates for maximum buckling load capacity. Here, JAYA algorithm, along with Salp Swarm Algorithm, Colliding Bodies Optimization, Grey Wolf Optimizer, and Genetic Algorithm with standard setting and self-adaptive version are implemented to the problem of composite laminates with 64 graphite/epoxy plies with conventional ply angles, under several bi-axial cases and panel aspect ratios. Optimization objective is to maximize the buckling load of symmetric and balanced laminated plate. Statistical analysis are performed for six cases and the results are compared in terms of mean, standard deviation, the coefficient of variation, best and worst solutions, accompanied by the percentage of the independent runs that found the global optimum \(\left( {{R_{{\text{op}}}}} \right)\) and near global optimum \(\left( {{R_{{\text{no}}}}} \right)\). The Kruskal–Wallis nonparametric test is also utilized to make further confidence in the examinations. Numerical results show the high capability of the JAYA algorithm for maximizing the buckling capacity of composite plates.

     

A molecular model for carbon black primary particles with internal nanoporosity

A molecular model of primary particles of porous carbon black has been developed. Using the hexagonal graphite sheets as building units, we simulated formation of carbon particles consisting of a core–shell structure. Several structural properties of carbon were examined. Graphite layers arrange in a concentric fashion in the shell region near the external surface of carbon. This trend gradually diminishes toward the center of carbon particles, resulting in an amorphous characteristic in the core region. In line with XRD experiments, our simulations show that about half of the graphite sheets in the carbon shell form microcrystalline domains typically consisting of 2–5 layers with a broad interlayer spacing of 0.34–0.4 nm. Starting from nonporous carbon particles with a high density of 2 g/cm³, a ‘digging’ approach was further developed to particularly model the internal nanoporosity of mesoporous carbon materials that are often obtained by the silica templating technique. The validity of the modeling technique to generate pores inside carbon particles is discussed in view of reproducing targeted PSDs.     

Fabrication of hydroxyapatite blended cyclic type polylactic acid and poly (ε-caprolactone) tissue engineering scaffold

The ultimate goal of tissue engineering serves to repair, restore damaged tissue or organ due to accident or disease. In this research, we are aimed at investigating the feasibility of processing cyclic type polylactic acid (PDLLA)/poly(ε-caprolactone) (PCL)/hydroxyapatite (HA) biomaterial into tissue engineering scaffold (TES) with variable mechanical properties, well interconnected pore architecture, and controlled hydrophilicity. For this, an in-house built bone scaffold 3D printing (BS3P) system was applied to two biomaterials, namely PDLLA-PCL and HA-PCL. These two biomaterials were produced by optimizing the robotic control system. Morphological investigation by scanning electron microscope (SEM) revealed both TES formed by new materials able to show honeycomb-like architectures, excellent fusion at the filament junctions, high uniformity, complete interconnectivity, and controlled channel characteristics of the TES. Compression tests align with the typical behavior of a porous material undergoing deformation. In vitro cell culture study and confocal laser microscopy (CLM) showed enhanced cell adhesion, proliferation, and extracellular matrix (ECM) formation. The results demonstrated the eligibility of the BS3P system to produce TES, and the suitability of the new biomaterial scaffolds in enhancing cell biocompatibility.     

RORI-based countermeasure selection using the OrBAC formalism

Attacks against information systems have grown in sophistication and complexity, making the detection and reaction process a challenging task for security administrators. In reaction to these attacks, the definition of security policies is an effective way to protect information systems from further damages, but it requires a great expertise and knowledge. If stronger security policies can constitute powerful countermeasures, inappropriate policies, on the other hand, may result in disastrous consequences for the organization. The implementation of stronger security policies requires in many cases the evaluation and analysis of multiple countermeasures. Current research promotes the implementation of multiple countermeasures as a strategy to react over complex attacks; however, the methodology is either hardly explained or very complicated to implement. This paper introduces a well-structured approach to evaluate and select optimal countermeasures based on the return on response investment (RORI) index. An implementation of a real case study is provided at the end of the document to show the applicability of the model over a mobile money transfer service. The service, security policies and countermeasures are expressed using the OrBAC formalism.     

MicroRNAs in Brain Metastases: Potential Role as Diagnostics and Therapeutics

Brain metastases remain a daunting adversary that negatively impact patient survival. Metastatic brain tumors affect up to 45% of all cancer patients with systemic cancer and account for ~20% of all cancer-related deaths. A complex network of non-coding RNA molecules, microRNAs (miRNAs), regulate tumor metastasis. The brain micro-environment modulates metastatic tumor growth; however, defining the precise genetic events that promote metastasis in the brain niche represents an important, unresolved problem. Understanding these events will reveal disease-based targets and offer effective strategies to treat brain metastases. Effective therapeutic strategies based upon the biology of brain metastases represent an urgent, unmet need with immediate potential for clinical impact. Studies have demonstrated the ability of miRNAs to distinguish normal from cancerous cells, primary from secondary brain tumors, and correctly categorize metastatic brain tumor tissue of origin based solely on miRNA profiles. Interestingly, manipulation of miRNAs has proven effective in cancer treatment. With the promise of reduced toxicity, increased efficacy and individually directed personalized anti-cancer therapy, using miRNA in the treatment of metastatic brain tumors may prove very useful and improve patient outcome. In this review, we focus on the potential of miRNAs as diagnostic and therapeutic targets for the treatment of metastatic brain lesions.     

On Analytic Continuation of Solutions of Linear Partial Differential Equations

We study analytic continuation properties of solutions of linear partial differential equations of Cauchy–Kowalewski type, with respect to one complex variable in sectors of infinite radius. Growth estimates are also investigated. 2000 Mathematics Subject Classification. 35C10, 35C20.     

Sensory and quality parameters of raw and processed Chicory-Hindbeh,a commonly consumed dark leafy green in Lebanon (Cichorium intybus L.) during frozen storage

This work aimed at assessing the effect of heat treatment and frozen storage on the sensory and chemical properties of chicory with the goal of optimizing the heat pretreatment-storage condition to best preserve the chemical and sensory properties of chicory. Raw, boiled (10 min), blanched (90 °C for 60 s) and steamed (for 20 s) chicory samples were produced and stored at −6 °C, −12 °C or −18 °C for 4 months. Chemical analyses (moisture, ash, vitamin C, peroxidase activity, chlorophyll and color) and sensory evaluation (QDA and hedonic evaluation) were conducted. Treatment significantly influenced all chemical variables (p < 0.001), except for moisture; and so did freezing temperatures for a-value (p < 0.001), chlorophyll-a, peroxidase activity, vitamin C and ash (p < 0.01), total chlorophyll, moisture and b-value (p < 0.05). Differences were obtained for age for all chemical variables (p < 0.001). Treatments affected consumers' acceptability of chicory and QDA showed that boiled chicory was significantly more tender, less chewy and crunchy and needed less time to disintegrate than other samples. PCA showed that PC1 and PC2 separated attributes based on type and intensity of treatments, respectively. It is recommended to use blanching at 90 °C for 60 s and freezing at −12 °C or −18 °C to best preserve the quality of chicory.     

Computer-Aided Graphical Analysis of Bridges under Vehicular Loading

A computer-based, graphical approach is presented to construct the Influence Profile for determinate bridge structures that are subjected to multiple axle loads. An Influence Profile represents the variation of an internal or external force, or moment, at a specific location of a structure, under loading by an actual vehicle (e.g., AASHTO HS-20 truck, American Railway Engineering and Maintenance-of-Way Association (AREMA) Cooper E-80 train). The technique works by scaling the influence line ordinates by the individual axle weights of the vehicle, and by applying distance delays to account for the horizontal separation between axles. The scaled and shifted influence lines for individual axle loads are then superimposed graphically to obtain the effect of the entire vehicle. Beam and truss examples are given to illustrate the technique. A simple method is also presented for constructing influence profiles for compound systems, where the load is transferred through the deck and floor beams to the superstructure. Because of its graphical concept, the technique provides a practical approach for evaluating the force effects caused by an actual vehicular load; it is also well suited for teaching purposes.     

Characterization of an artificial skull cap for cranio-maxillofacial surgery training

Cranial grafts are favored to reconstruct skeletal defects because of their reduced resorption and their histocompatibility. Training possibilities for novice surgeons include the “learning by doing” on the patient, specimens or simulators. Although the acceptance of simulators is growing, the major drawback is the lack of validated bone models. The aim of this study was to create and validate a realistic skull cap model and to show superiority compared to a commercially available skull model. Characteristic forces during machinery procedures were recorded and thickness parameters from the bony layers were obtained. The thickness values of the bone layers of the developed parietal bone were comparable to the human ones. Differences between drilling and sawing forces of human and artificial bones were not detected using statistical analysis. In contrast the parameters of the commercially available skull model were significantly different. However, as a result, a model-based simulator for tabula externa graft lift training, consisting of a brain, skull bone cap and covering soft tissues was created. This simulator enables the training of all procedural steps of a “split thickness graft lift”. In conclusion, an artificial skull cap suitable for parietal graft lift training was manufactured and validated against human parietal bones.