Polarimetric Multi-View Inverse Rendering

A polarization camera has great potential for 3D reconstruction since the angle of polarization (AoP) of reflected light is related to an object's surface normal. In this paper, we propose a novel 3D reconstruction method called Polarimetric Multi-View Inverse Rendering (Polarimetric MVIR) that effectively exploits geometric, photometric, and polarimetric cues extracted from input multi-view color polarization images. We first estimate camera poses and an initial 3D model by geometric reconstruction with a standard structure-from-motion and multi-view stereo pipeline. We then refine the initial model by optimizing photometric and polarimetric rendering errors using multi-view RGB and AoP images, where we propose a novel polarimetric rendering cost function that enables us to effectively constrain each estimated surface vertex's normal while considering four possible ambiguous azimuth angles revealed from the AoP measurement. Experimental results using both synthetic and real data demonstrate that our Polarimetric MVIR can reconstruct a detailed 3D shape without assuming a specific polarized reflection depending on the material.Comment: Paper accepted in ECCV 202

Neglected Tropical Diseases of the Middle East and North Africa: Review of Their Prevalence, Distribution, and Opportunities for Control

The neglected tropical diseases (NTDs) are highly endemic but patchily distributed among the 20 countries and almost 400 million people of the Middle East and North Africa (MENA) region, and disproportionately affect an estimated 65 million people living on less than US$2 per day. Egypt has the largest number of people living in poverty of any MENA nation, while Yemen has the highest prevalence of people living in poverty. These two nations stand out for having suffered the highest rates of many NTDs, including the soil-transmitted nematode infections, filarial infections, schistosomiasis, fascioliasis, leprosy, and trachoma, although they should be recognized for recent measures aimed at NTD control. Leishmaniasis, especially cutaneous leishmaniasis, is endemic in Syria, Iran, Iraq, Libya, Morocco, and elsewhere in the region. Both zoonotic (Leishmania major) and anthroponotic (Leishmania tropica) forms are endemic in MENA in rural arid regions and urban regions, respectively. Other endemic zoonotic NTDs include cystic echinococcosis, fascioliasis, and brucellosis. Dengue is endemic in Saudi Arabia, where Rift Valley fever and Alkhurma hemorrhagic fever have also emerged. Great strides have been made towards elimination of several endemic NTDs, including lymphatic filariasis in Egypt and Yemen; schistosomiasis in Iran, Morocco, and Oman; and trachoma in Morocco, Algeria, Iran, Libya, Oman, Saudi Arabia, Tunisia, and the United Arab Emirates. A particularly noteworthy achievement is the long battle waged against schistosomiasis in Egypt, where prevalence has been brought down by regular praziquantel treatment. Conflict and human and animal migrations are key social determinants in preventing the control or elimination of NTDs in the MENA, while local political will, strengthened international and intersectoral cooperative efforts for surveillance, mass drug administration, and vaccination are essential for elimination

Thermodynamic and mechanical characterisation of kaolin clay

This study deals with experimental thermodynamic and rheological characterization of kaolin. Water sorption isotherms of kaolin were determined for three temperatures (30, 50 and 70°C). Desorption isotherms were fitted by using five models (GAB, BET, Henderson modified, Adam and Shove, Peleg) among the most used ones in literature. The GAB model was found to be the most suitable for describing the relationship between equilibrium moisture content and water activity for the whole range of temperature (30-70°C) and relative humidity(0-100%). Desorption enthalpy and entropy were determined. The desorption enthalpy decreases with increasing moisture content. The density and the shrinkage of the material and the Young’s modulus variations as a function of moisture content were determined experimentally. The Young modulus varies between 0.1 MPa and 14 MPa. The viscoelastic parameters of kaolin were also determined by using a series of Prony

Thermodynamic and mechanical characterisation of kaolin clay

This study deals with experimental thermodynamic and rheological characterization of kaolin. Water sorption isotherms of kaolin were determined for three temperatures (30, 50 and 70°C). Desorption isotherms were fitted by using five models (GAB, BET, Henderson modified, Adam and Shove, Peleg) among the most used ones in literature. The GAB model was found to be the most suitable for describing the relationship between equilibrium moisture content and water activity for the whole range of temperature (30-70°C) and relative humidity(0-100%). Desorption enthalpy and entropy were determined. The desorption enthalpy decreases with increasing moisture content. The density and the shrinkage of the material and the Young’s modulus variations as a function of moisture content were determined experimentally. The Young modulus varies between 0.1 MPa and 14 MPa. The viscoelastic parameters of kaolin were also determined by using a series of Prony

Experimental study and modelling of water sorption/desorption isotherms on two agricultural products: Apple and carrot

This work is focused on some properties of dried apple (Red Chief) and carrot (Misky). Water sorption isotherms of carrot and apple were investigated at three temperatures: 30, 40 and 60°C, corresponding to drying temperatures, by the static method consisting of the use of different sulphuric acid solutions. Guggenheim-Anderson-de Boer (G.A.B) model is found to describe the experimental curves better than Henderson, Hasley and Oswin models with a correlation coefficient superior to 0.97 for both products. The hysteresis phenomenon was clearly observed in the case of apple isotherms. The experimental data were also used to determine the isosteric enthalpy of desorption of apple and carrot. The isosteric enthalpy of desorption decreased with increase in moisture content and the trend became asymptotic

Transfer Phenomena During the Drying of a Shrinkable Product: Modeling and Simulation

International audienc

Material parameter extraction in THz-TDS using a converging beam transfer function

We demonstrate a parameter extraction algorithm based on a theoretical transfer function, which takes into account a converging THz beam. Using this, we successfully extract material parameters from data obtained for a quartz sample with a THz time domain spectrometer