Roughness Area Research Articles

No‐Flow Fraction (NFF) Permeability Model for Rough Fractures Under Normal Stress

AbstractFlow through rock fractures is frequently represented using models that correct the cubic law to account for the effects of roughness and contact area. However, the scope of such models is often restricted to relatively smooth aperture fields under small confining stresses. This work studies the link between fracture permeability and fracture geometry under normal loads. Numerical experiments are performed to deform synthesized aperture fields of various correlation lengths and roughness values under normal stress. The results demonstrate that aperture roughness can more than triple for applied stresses up to 50 MPa – exceeding the valid range for roughness in most previously published models. Investigating the relationship between permeability and contact area indicates that the increase in flow obstructions due to the development of new contact points strongly depends on the correlation length of the unloaded aperture field. This study eliminates these dependencies by employing a parameter known as the No‐Flow Fraction (NFF) to capture the effect of flow stagnation zones. With this concept, a new Cubic‐law‐based permeability model is proposed that significantly improves the accuracy of permeability estimations, compared to previous models. For cases, where the NFF is difficult to obtain, we introduce an empirical relationship to estimate the parameter from the aperture roughness. The new models yield permeability estimates accurate to within a factor of 2 of the simulated permeability in over three‐quarters of the 3,000 deformed fractures studied. This compares with typical deviations of at least one order of magnitude for previously published permeability models.

VOCs reduction in bitumen binder with optimally designed Ca(OH)2-incorporated zeolite

Environment-friendly pavement materials are one of the biggest concerns in infrastructure material design. Bitumen binder is a widely used infrastructure material for highways, but it releases VOCs (volatile organic compounds) during its life time service. VOCs release from bitumen binder will not only lead to environmental pollution, but also result in degradation of pavement performance. This research focused on reducing VOCs in bitumen binder by self-designed Ca(OH)2-incorporated zeolite. Characteristics of Ca(OH)2-incorporated zeolite and its VOC reduction were studied. The research results indicate that decreasing the mole ratio of Al3+/Ca2+ will increase the surface roughness and specific surface area of Ca(OH)2-incorporated zeolite, with potential for higher VOCs reduction. The 1:2 Ca(OH)2-incorporated zeolite mainly contains mesoporous structure. With its water molecules, occluded in cavities and channels, being released during heating, the viscosity of bitumen binder also decreases resulting in a warm mix that positively influences the reduction of VOCs emission further. Adding Ca(OH)2-incorporated zeolite into bitumen can effectively reduce both total emission and toxicity of bitumen VOCs. An optimal heating temperature is needed to obtain peak reduction on VOCs. At warm mix temperature, a remarkable reduction of PAHs release can be achieved due to the Ca(OH)2-incorporated zeolite’s catalytic properties. More than 37% of total VOCs reduction can be achieved by the self-designed Ca(OH)2-incorporated zeolite.

Optimization of the microstructure of TiO2 photocatalytic surfaces created by Plasma Electrolytic Oxidation of titanium substrates

UV treatments are commonly employed for removal of pollutants from water in industrial environments. Introduction of a suitable photocatalyst can be beneficial in improving the energy efficiency. This commonly involves creating powerful reactive oxygen species that are able to degrade pollutants. However, the photocatalyst is required to have both high surface area (accessible to irradiation from the light source) and to be mechanically robust. TiO2 is a well-known photocatalyst, suitable for use under UV illumination. This paper concerns production of photocatalytic TiO2 via Plasma Electrolytic Oxidation (PEO) of titanium substrates. PEO of Ti commonly results in highly porous TiO2 coatings that adhere strongly to a robust metallic substrate. Characteristics of the electrical discharges, which are central to the PEO process, have been studied using high-speed photography. These results are correlated with the microstructure of the resultant coating. The photocatalytic performance has been evaluated under UV-C illumination, using urea as a model pollutant, and modelling of liquid flow over the PEO surfaces has been performed using COMSOL. Photocatalytic activity is enhanced on samples with high surface roughness and high surface area, which tend to be produced after intermediate processing times (8 min). This is explained in terms of how fluid flow is disrupted over rough surfaces, reducing the thickness of the hydrodynamic boundary layer and increasing the interaction between pollutant and catalytic surface.

N,S‐Codoped hollow carbon dodecahedron/sulfides composites enabling high‐performance lithium‐ion intercalation

AbstractLithium‐ion batteries are the predominant energy storage devices for portable electronic devices and hold great promise for renewable energies and sustainability. High capacity and long‐life anode materials are highly desired for the next‐generation Li‐ion battery with high energy density. Herein, a high‐performance anode electrode constructed with cobalt and zinc sulfides nanocrystals embedded within a nitrogen and sulfur co‐doped porous carbon is successfully designed bimetal‐organic frameworks as the precursor. Benefiting from synergistic effects of bimetal sulfides, the unique rhombohedral dodecahedral nanostructure with rough surface area and N,S‐codoped carbon matrix, such an anode material presents superior initial reversible capacity of 938.2 mA h g−1 with a high‐capacity retention of 65.6% after 100 cycles at 150 mA/g. The effective nanostructure design is expected to open a venue to construct high‐performance materials for energy and environment applications.

Phase-field gradient theory

We propose a phase-field theory for enriched continua. To generalize classical phase-field models, we derive the phase-field gradient theory based on balances of microforces, microtorques, and mass. We focus on materials where second gradients of the phase field describe long-range interactions. By considering a nontrivial interaction inside the body, described by a boundary-edge microtraction, we characterize the existence of a hypermicrotraction field, a central aspect of this theory. On surfaces, we define the surface microtraction and the surface-couple microtraction emerging from internal surface interactions. We explicitly account for the lack of smoothness along a curve on surfaces enclosing arbitrary parts of the domain. In these rough areas, internal-edge microtractions appear. We begin our theory by characterizing these tractions. Next, in balancing microforces and microtorques, we arrive at the field equations. Subject to thermodynamic constraints, we develop a general set of constitutive relations for a phase-field model where its free-energy density depends on second gradients of the phase field. A priori, the balance equations are general and independent of constitutive equations, where the thermodynamics constrain the constitutive relations through the free-energy imbalance. To exemplify the usefulness of our theory, we generalize two commonly used phase-field equations. We propose a ‘generalized Swift–Hohenberg equation’—a second-grade phase-field equation—and its conserved version, the ‘generalized phase-field crystal equation’—a conserved second-grade phase-field equation. Furthermore, we derive the configurational fields arising in this theory. We conclude with the presentation of a comprehensive, thermodynamically consistent set of boundary conditions.

Fatigue behavior of bonded lithium disilicate glass-ceramic simplified restorations is not damaged by the finishing/grinding of the bonding surface of dentin analogue material

Fiber-reinforced epoxy resin has been utilized as dentin-analogue material in fatigue tests, owing to their similar resin adhesion and biomechanical behavior. The procedures for finishing the dental surface change the surface topography, promoting variable roughness in the prepared substrate, which influences the interaction between the resin cement and the bonding surface. This study evaluated the influence of finishing by grinding the bonding surface of dentin analogue material (epoxy resin) on the fatigue behavior of adhesively cemented lithium disilicate glass-ceramic simplified restorations. Epoxy resin discs (Ø = 10 mm, thickness = 2 mm) were allocated into four groups considering the “grinding” factor: CTRL – no grinding; G – grinding with coarse grit diamond bur; G + F – grinding with coarse grit diamond bur followed by fine grit diamond bur; G + F + FF – grinding with coarse grit diamond bur followed by fine and extra fine grit diamond burs. After grinding, the discs were cleaned, etched (10% hydrofluoric acid; 1 min) and received a primer coating. Lithium disilicate discs (Ø = 10 mm, thickness = 1 mm) were also etched (5% hydrofluoric acid; 20 s) and received a silane agent, and then were adhesively cemented onto epoxy resin discs and subjected to a step-stress fatigue tests at 20 Hz, 10,000 cycles/step with a step-size of 100 N. Fractography, surface topography, roughness and fractal dimension analyses were performed. The CTRL group showed the lowest fatigue performance, roughness and surface area values. No statistical difference for fatigue performance and surface area was observed among the ‘grinding’ groups, having a decreasing roughness relationship (G > G + F > G + F + FF). Therefore, the grinding the preparation surface with distinct diamond bur sequence has no effect on the fatigue behavior of lithium disilicate restorations, as well as, grinding promotes improved results over a non-ground surface. Thus, it is important to pay attention to managing the dentin analogue surface considering that the epoxy resin with unground surfaces induces lower fatigue behavior.

Experimental investigation on laser cutting of PMMA sheets: Effects of process factors on kerf characteristics

This paper reports an experimental investigation on continuous CO2 laser cutting of polymethylmethacrylate (PMMA) sheet. The influence of four process factors (laser power, cutting speed, assisting gas pressure and sheet thickness) on five process responses (kerf deviation, top heat affected zone, bottom heat affected zone, maximum surface roughness and rough area) has been investigated. The experimental plan was established based on Taguchi L18 mixed design. The kerf geometry and heat affected zones have been measured using polarising light microscopy technique, while the surface roughness was evaluated using 3D laser scanning confocal microscope. Regression models have been derived to correlate different process responses with different process factors. The cut surface could be classified into three zones: rough zone, moderate zone and soft zone. The rough area is increased by increasing gas pressure and laser power and by decreasing the sheet thickness and cutting speed. Increased kerf deviation has been observed at high cutting speed, laser power and gas pressure. High laser power and low cutting speed produced worst surface roughness and wide heat affected zone. Therefore, it is recommended to use low laser power and high cutting speed to minimize the heat affected zone and the surface roughness. However, increasing the cutting speed may result in high kerf deviation.

Preparation of phosphate conversion coating on laser surface textured surface to improve corrosion performance of magnesium alloy

In this work, we proposed a surface modification strategy to improve corrosion resistance of magnesium alloy by combining laser surface texturing (LST) with phosphate conversion coating (PCC). The surface and section morphologies, adhesive performance and electrochemical corrosion properties of the coated samples were investigated. Results demonstrate that the multimodal surface roughness and high specific area generated by LST facilitate the deposition of coating, increase the adhesion of coating and reduce the shedding rate of coating in the scratch test. Electrochemical analyses reveal that the coated sample with LST pretreatment shows superior corrosion properties, and fewer areas were damaged by corrosive medium compared with the coated sample without LST. Immersion test results reveal that LTC sample shows the best long-term corrosion resistance among all samples.The underlying mechanisms of the PCC with LST pretreatment to improve the anticorrosive performance of Mg alloys are proposed.

Predicting the Drag of Rough Surfaces

Reliable full-scale prediction of drag due to rough wall-bounded turbulent fluid flow remains a challenge. Currently, the uncertainty is at least 10%, with consequences, for example, on energy and transport applications exceeding billions of dollars per year. The crux of the difficulty is the large number of relevant roughness topographies and the high cost of testing each topography, but computational and experimental advances in the last decade or so have been lowering these barriers. In light of these advances, here we review the underpinnings and limits of relationships between roughness topography and drag behavior, focusing on canonical and fully turbulent incompressible flow over rigid roughness. These advances are beginning to spill over into multiphysical areas of roughness, such as heat transfer, and promise broad increases in predictive reliability.

Influence of Nafion template on the kinetics of anodic Pt based pluri-metallic catalyst for ethanol electro-oxidation

This paper involves a novel approach for synthesizing single Pt and binary catalysts, PtRu of different compositions by pulse electrodepostion technique using Nafion as template during fabrication of the anode, whereby maximum utilization of nanoparticle is possible. In this investigation, Nafion templated metal nanoparticles were characterized by X-ray Diffraction Analysis (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM) techniques. The surface morphology and topographical analysis of the templated catalysts reveal the existence of fairly well distributed nano size particles imparting high roughness area to the catalyst matrix. By use of Nafion template the best catalyst formulation to promote the ethanol oxidation was identified to be one with 23 at.% Ru in the binary matrix. Kinetic investigations on ethanol electro-oxidation were conducted through various electrochemical techniques like cyclic voltammetry (CV), polarization, chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS).

ENHANCED ENDOSCOPY FOR THE DIAGNOSIS OF GASTRICANTRALINTESTINAL METAPLASIA

Background: The detection of early gastric cancer may improve survival and avoid major gastric surgeries. Gastric Intestinal Metaplasia (GIM) is a precancerous lesion of the stomach. Screening for GIM may therefore lead to early detection of gastric neoplastic lesions. Objective: This study was designed to determine the effect of conventional Narrow Band Image (NBI) in combination with acetic acid (AA-NBI) on the diagnosis of antral GIM. Patients and Methods: The present study was performed in 100 consecutive adults who required endoscopic examination at AL Hussein University Hospital, Department of Internal Medicine, Endoscopy Unit, Conventional white-light endoscopy (WLE), NBI and AA-NBI was performed in all patients by the same endoscopist during a single procedure with a GIF Q290 endoscope (Olympus Medical Systems, Tokyo, Japan), All suspicious antral gastric lesions was photographed. Any abnormal mucosal change, such as localized discoloration and rough areas, was considered indicative of GIM lesions. Results: Fifty-six (56.0%) out of the 100 individuals examined were found to have GIM (by biopsy), of which 34 (60.7%) were diagnosed correctly by NBI (sensitivity 66.7% and specificity 68.2%) and 42 (75%) were correctly identified by AA–NBI (sensitivity 75% and specificity 73.91%), as compared to only 24 (42.86%) by WLE (sensitivity 42.86% and specificity 37.5%). Therefore, the sensitivity of AA–NBI in the diagnosis of GIM was significantly higher than NBI (p < 0.05) and WLE (p < 0.001). Our study indicates that AA-NBI can improve the accuracy of endoscopy-targeted biopsies for GIM. Conclusion: Acetic acid staining combined with NBI was of a higher sensitivity and specificity in the diagnosis of intestinal metaplasia in gastric mucosa, which was in good consistency with the pathological diagnosis. Compared with the normal NBI, it was more capable to detect lesions of intestinal metaplasia in gastric mucosa, improved the accuracy of targeted biopsy to intestinal metaplasia, and has an important significance in the early detection and treatment of tumors.

ENHANCED ENDOSCOPY FOR THE DIAGNOSIS OF GASTRICANTRALINTESTINAL METAPLASIA

Background: The detection of early gastric cancer may improve survival and avoid major gastric surgeries. Gastric Intestinal Metaplasia (GIM) is a precancerous lesion of the stomach. Screening for GIM may therefore lead to early detection of gastric neoplastic lesions. Objective: This study was designed to determine the effect of conventional Narrow Band Image (NBI) in combination with acetic acid (AA-NBI) on the diagnosis of antral GIM. Patients and Methods: The present study was performed in 100 consecutive adults who required endoscopic examination at AL Hussein University Hospital, Department of Internal Medicine, Endoscopy Unit, Conventional white-light endoscopy (WLE), NBI and AA-NBI was performed in all patients by the same endoscopist during a single procedure with a GIF Q290 endoscope (Olympus Medical Systems, Tokyo, Japan), All suspicious antral gastric lesions was photographed. Any abnormal mucosal change, such as localized discoloration and rough areas, was considered indicative of GIM lesions. Results: Fifty-six (56.0%) out of the 100 individuals examined were found to have GIM (by biopsy), of which 34 (60.7%) were diagnosed correctly by NBI (sensitivity 66.7% and specificity 68.2%) and 42 (75%) were correctly identified by AA–NBI (sensitivity 75% and specificity 73.91%), as compared to only 24 (42.86%) by WLE (sensitivity 42.86% and specificity 37.5%). Therefore, the sensitivity of AA–NBI in the diagnosis of GIM was significantly higher than NBI (p < 0.05) and WLE (p < 0.001). Our study indicates that AA-NBI can improve the accuracy of endoscopy-targeted biopsies for GIM. Conclusion: Acetic acid staining combined with NBI was of a higher sensitivity and specificity in the diagnosis of intestinal metaplasia in gastric mucosa, which was in good consistency with the pathological diagnosis. Compared with the normal NBI, it was more capable to detect lesions of intestinal metaplasia in gastric mucosa, improved the accuracy of targeted biopsy to intestinal metaplasia, and has an important significance in the early detection and treatment of tumors.

Titanium Bioactive Surface Formation Via Alkali and Heat Treatments for Rapid Osseointegration

Titanium and its alloys are widely used as implant materials and many studies to accelerate the osseointegration have been performed. This work aims to evaluate the formation of a bioactive surface in commercially pure titanium (cp-Ti) grade 4 after alkali (AT) and heat treatments at 600 °C (AHT600) and 900 °C (AHT900). Characterization techniques were SEM, AFM, Raman, TF-XRD, wettability, nanoindentation and indentation adhesion. Additionally, SBF soaking tests were performed to evaluate apatite growth and showed that alkali and heat treatment accelerates apatite growth. The AT samples formed sodium hydrogen titanate (1 µm thick), and AHT600 and AHT900 formed sodium titanate (1 µm thick), while rutile TiO2 increased with temperature, reaching up to 5 µm thick and the surface changed from slightly hydrophilic to fully hydrophilic. Roughness and surface area increased, especially in AHT900. The hardness of the surface layer was significantly increased by the heat treatment.

Insights of remote sensing data to surmount rainfall/runoff data limitations of the downstream catchment of Pineios River, Greece

Efficient rainfall/runoff data modeling necessitates field data availability. Remote and rough terrain areas restrict data collection that leads to less reliable simulated models. Consequently, complete geographic databases are the quest to conduct over the catchment under investigation. The hydrologic model developed for this research based on different return periods (2, 5, 10, 25, 50, 100, and 200 years) gave significant discharge outputs. It was found that a basin average precipitation having a return period of 5 years yields a peak discharge of 1032.7 m3/s with the time of peak occurring 23.25 h after the event has started. It results in a volume of 79.9 × 106 m3. A storm event having a return period of 200 years, with basin average rainfall approximately two times more intense than the above yields an enormous discharge of 2191.1 m3/s and an accumulative volume of water of 158.8 × 106 m3. Accordingly, the catchment cannot accommodate such significant volumes of water and flooding becomes unavoidable. Therefore, hydrological, and hydraulic models can support decision-makers in correspondence to the catchment management problems for the sustainable and economic development of the wider area, by providing systematic and consistent information.

Sheath of distal tendon of semimembranosus muscle and it's functional significance

Introduction: Semimembranosus (SM) muscle is important in maintaining the stability of knee joint, and the distal end of it's tendon is not only complex but has been described differently in the available literature, which is quite perplexing. How a muscle with such divergent attachments can efficiently perform it's functions? Hence a detailed study of the distal semimembranosus tendon unit was undertaken. Material and Methods: One hundred lower limbs (Rt-50; lt.-50) were utilized for the present study. The posterior surface of SM was exposed and as the main tendon could not be traced to its insertion hence a vertical incision was made on the posterior surface of this tendon and this lead to the splitting of the tendon-sheath which exposed the thick shining distal tendon of SM. Results: Surprisingly, it was found that the main tendon of the SM (SMT) was surrounded by a fibrous sheath which was derived from the main muscle mass in the lower part of the thigh and in the majority of cases it was separated from it by a synovial space. Traced inferiorly it was observed that it is the sheath that spreads out to various divergent destinations described in the literature, whereas the main tendon gets attached to the groove on the posterior aspect of the medial condyle of tibia and a rough triangular area below the groove. Discussion and Conclusion: It is the nature's ingenuity that a single muscle with such divergent distal attachments can still efficiently perform its functions due to the formation of a sheath of distal tendon of SM.

Mechanism of megaloblastic anemia combined with hemolysis

ABSTRACT Megaloblastic anemia (MA) patients often exhibit hemolysis, but it is not clear whether there are other hemolytic mechanisms in addition to intramedullary hemolysis. We retrospectively analyzed the clinical characteristics of 124 MA patients, measured erythrocyte physical parameters in two patients with hemolysis and one healthy volunteer by atomic force microscopy, and measured 18F-FDG uptake in one MA patient with hemolysis. In multivariate analysis, hemolysis was associated with mean corpuscular volume (MCV) and indirect bilirubin. A receiver operating characteristic curve analysis, with sensitivity of 83.1% and specificity of 68.7%, suggested that the MCV cutoff value that predicts hemolysis is 116.4 fL. Hb was negatively correlated with MCV in the hemolysis group (r = −0.317, P = 0.007) but not in the nonhemolysis group. The erythrocyte peak-valley value, average cell surface roughness and surface area in the MA patients with hemolysis were significantly lower than those in controls (P < 0.05). 18F-FDG uptake by the liver and spleen was diffuse and increased in MA patients undergoing hemolysis. MA combined with extramedullary hemolysis could be caused by macrophages removing mechanically damaged erythrocytes and the retention of erythrocytes with decreased deformability when blood circulates through narrow spaces in the liver and spleen.

Cabbage-derived three-dimensional cellulose scaffold-induced osteogenic differentiation of stem cells.

Herbal-derived three-dimensional scaffolds have a unique structure that represents the natural cellular microenvironment and can be potentially used for tissue engineering applications. In the present study, cabbage (Cb) leaves were decellularized and then their characteristics, such as surface roughness, wettability, porosity, mechanical properties, and specific surface area, were investigated. After that, scaffold osteoinductivity was studied by bone-marrow-derived mesenchymal stem cells (BM-MSCs) osteogenic differentiation while growing on the decellularized Cb leaves. Cells mineralization, calcium secretion, alkaline phosphatase (ALP) activity, and expression levels of bone-related genes were determined during the differentiation process. Our results from the structural characterization of the scaffolds demonstrated that decellularized Cb leaves are good candidates for bone differentiation in terms of surface roughness, mechanical properties,and interconnected pores. Osteogenic differentiation evaluation of the BM-MSCs determined that the cell's ALP activity and mineralization were increased significantly while cultured on the decellularized Cb leaves compared to the cells cultured on the culture plate as a control. Besides, Runx2, ALP, collagen-1 (Col-I), and osteocalcin genes were expressed in cells cultured on decellularized Cb leaves significantly higher than cells cultured on the culture plate. Based on these results, it can be concluded that the decellularized Cb scaffold has great potential for promoting BM-MSCs proliferation and osteogenic differentiation.

Prominent c-axis oriented Si-doped ZnO thin film prepared at low substrate temperature in RF magnetron sputtering and its UV sensing in p-Si/n-SZO heterojunction structures

Considering the effectiveness of silicon (Si) doping in zinc oxide (ZnO) to produce Si-doped zinc oxide (SZO) for good quality transparent and conducting oxide (TCO) films, different varieties of ZnO and SZO films have been grown by changing the substrate temperature (TS), radiofrequency (RF) power and coverage (Ψ%) on the erosion area of the ZnO target using the c-Si wafer as the source of Si dopant in RF magnetron sputtering. Prominent c-axis orientation in SZO thin films and its gradual evolution on parametric changes have been systematically studied. For undoped ZnO films grown via a gradual increase in the TS, the lattice constant (c), lattice strain and stress do not change substantially. However, the grain size significantly increases, as shown by the changes in the position and full width at half maxima (FWHM) of the X-ray diffraction (XRD) peak corresponding to the (002) plane. Increasing the RF power increases the grain size and moderately decreases the c. On the contrary, upon the introduction of Si doping and its systematic escalation at increased Ψ%, the grain size linearly decreases. Upon increasing the RF power, the grain size in the SZO network increases and the magnitude of c decreases enormously, which signify the increased substitutional incorporation of the Si dopant in its Si4+ ionized state at the Zn2+ lattice site. In the SZO samples the magnitude of c, strain and stress decrease up to a certain level and then increase at elevated substrate temperature, indicating the occurrence of increased doping via Si incorporation, in contrast, at the interstitial position in the ZnO network. The RMS roughness, average roughness and surface area increase linearly with the RF power for both ZnO and SZO films. Preliminary achievements using the SZO films toward ultraviolet (UV) sensing utilizing its p-Si/n-SZO heterojunction structures has been presented.

Determination of Internal Waves Off the Coast of Morocco According to Earth Remote Sensing Data

This paper presents the results of a study of the internal wave isolation of the Northern coast of Morocco using synthetic aperture radar (SAR) images. A filter is applied to the remote sensing data to reduce the image grain, after which the direction of propagation of the wave is determined and its length is calculated. In most cases, internal waves appear on satellite images as quasi-periodic linear structures whose brightness is lower or higher than the background, which is well registered in the visible range and by synthetic aperture radar. When analyzing images off the coast of Morocco, internal waves were detected, the wave packet propagates in the direction from West to East. When comparing the obtained images with the bottom relief map, it can be assumed that the generation of internal waves is caused by the roughness of the bottom near the Northern coast of Morocco. The maximum wave length in the wave packet is almost 0.7 km, consists of at least 5 solitons, the prints of these solitons in the sea roughness area are visible in the images mainly in the Central part of a wave packet, the distance between a wave packet solitons is different. The wavelength decreases when moving to the back of a wave packet, which can be traced by changing the contrast on the site. As a result, internal waves were detected off the Northern coast of Morocco in rads images with a synthesized aperture, and the main characteristics of these waves were determined.

Crime Control and Everyday Life in the Victorian City: The Police and the Public, by David Churchill and Crime, Violence, and the Irish in the Nineteenth Century, edited by Kyle Hughes and Donald M. MacRaild

Reviewed by: Crime Control and Everyday Life in the Victorian City: The Police and the Public by David Churchill, and: Crime, Violence, and the Irish in the Nineteenth Century ed. by Kyle Hughes and Donald M. MacRaild William Meier (bio) Crime Control and Everyday Life in the Victorian City: The Police and the Public, by David Churchill; pp. xv + 290. Oxford and New York: Oxford University Press, 2017, £63.00, $85.00. Crime, Violence, and the Irish in the Nineteenth Century, edited by Kyle Hughes and Donald M. MacRaild; pp. xii + 289. Liverpool: Liverpool University Press, 2017, £85.00, $130.00. The volumes reviewed here testify to the enduring impact of E. P. Thompson, Douglas Hay, Bruce Lenman, V. A. C. Gatrell, and other social historians of crime whose pioneering scholarship explored plebeian experiences of, and resistance to, the centralization of the state’s law-and-order institutions between the late-eighteenth and mid-nineteenth centuries. Their work modeled ways of reading against the grain of official sources to recover alternative histories, and collectively they poured the foundation for the accepted narrative of British criminal justice history: that, by mid-Victorian times, political economy had triumphed over moral economy and the professionalized policeman state had overtaken older forms of crime control. Not so fast, says David Churchill, who, in Crime Control and Everyday Life in the Victorian City: The Police and the Public, rejects this “state monopolization thesis” and asks us to consider a longer timeline for the modernization of British criminal justice (3). Focusing on relations between police and public in Victorian Manchester, Leeds, and Liverpool, Churchill proposes instead that Victorian criminal justice resembled a “mixed economy” that empowered citizens to prevent property crime (241). Indeed, Churchill sees more continuity than change from the eighteenth century through the nineteenth. Far from being sidelined by the professional police, ordinary people continued to do much of the work of the criminal justice system: they discovered and reported crimes, confronted and apprehended wrongdoers, recovered stolen property, and concluded private, out-of-court settlements with offenders. Such popular initiative was vital, according to Churchill, to compensate for the deficiencies of the new blue-coated Bobbies. Dogged by poor recruitment and underfunding, professional police wielded little preventive impact on crime and resembled instead the old night-watch, acting as “generalists” who maintained urban order through such tedious tasks as curbing children’s games and street-corner gambling, shooing away beggars and street sellers, and removing orange peels from pavements (60). [End Page 683] Churchill succeeds in showing the unevenness of the Victorian state’s grip on crime control, and his impressive research in provincial archives provides welcome attention beyond London. But his micro-level evidence of everyday crime-fighting is insufficient to displace the consensus narrative about the centralization of state power over criminal justice: if judge, jailer, and constable did not quite monopolize the market, they were certainly the dominant firms. What truly blunts his analysis, though, is his view of the criminal justice system through the lens of the corporate, market-driven language of contemporary social science. Churchill’s method to “re-forge dialogue between history and criminology” misfires (7). Instead of dialogue, he makes nineteenth-century facts fit twenty-first-century jargon. For example, what Churchill calls a “‘preventative mentality’—a cautionary, consequentialist approach towards the security of one’s belongings” (138) that “sought to ‘responsibilize’ the civilian public in the governance of crime” simply meant that people locked up their belongings (144). Such abstractions wash out the finer details that a true social history would reveal. One wonders whether what he calls the “vernacular culture of criminal justice” was nothing more than locking one’s doors, securing one’s purse, and yelling, “Stop thief!” (258). The book is not, as Churchill claims, a “social history of the response to crime in the Victorian city.” His characters are one-dimensional and his categories of the social and the public are undifferentiated masses, a “largely anonymous multitude,” in his own words (257). For instance, Churchill notes in passing that police considered Irish immigrant quarters to be rough areas, but he makes no attempt to analyze how the Irish community in Britain related...